Update MQTT docs for consistency (#3759)

Makes some updates to the MQTT docs pages for spelling and grammar, and
also consistency.

source/_components/climate.mqtt.markdown

@@ -13,7 +13,7 @@ ha_release: 0.55
 ha_iot_class: "Local Polling"
 ---
 
-The `mqtt` climate platform let you control your MQTT enabled HVAC devices.
+The `mqtt` climate platform lets you control your MQTT enabled HVAC devices.
 
 The platform currently works in optimistic mode, which means it does not obtain states from MQTT topics, but it sends and remembers control commands.
 

source/_components/cover.mqtt.markdown

@@ -65,7 +65,7 @@ Configuration variables:
 
 ## {% linkable_title Examples %}
 
-In this section you find some real life examples of how to use this platform.
+In this section you will find some real life examples of how to use this platform.
 
 ### {% linkable_title Full configuration without tilt %}
 

source/_components/fan.mqtt.markdown

@@ -13,9 +13,9 @@ ha_release: 0.27
 ha_iot_class: depends
 ---
 
-The `mqtt` fan platform let you control your MQTT enabled fans.
+The `mqtt` fan platform lets you control your MQTT enabled fans.
 
-In an ideal scenario, the MQTT device will have a `state_topic` to publish state changes. If these messages are published with `RETAIN` flag, the MQTT fan will receive an instant state update after subscription and will start with correct state. Otherwise, the initial state of the fan will be `false`.
+In an ideal scenario, the MQTT device will have a `state_topic` to publish state changes. If these messages are published with a `RETAIN` flag, the MQTT fan will receive an instant state update after subscription and will start with the correct state. Otherwise, the initial state of the fan will be `false` / `off`.
 
 When a `state_topic` is not available, the fan will work in optimistic mode. In this mode, the fan will immediately change state after every command. Otherwise, the fan will wait for state confirmation from the device (message from `state_topic`).
 
@@ -56,7 +56,7 @@ Configuration variables:
 - **speeds** array (*Optional*): Valid entries for the list are `off`, `low`, `medium`, and `high`.
 
 <p class='note warning'>
-Make sure that your topic is an exact match. `some-topic/` and `some-topic` are different topics.
+Make sure that your topics match exactly. `some-topic/` and `some-topic` are different topics.
 </p>
 
 ## {% linkable_title Examples %}

source/_components/light.mqtt.markdown

@@ -14,11 +14,11 @@ ha_iot_class: depends
 
 The `mqtt` light platform lets you control your MQTT enabled lights. It supports setting brightness, color temperature, effects, flashing, on/off, RGB colors, transitions, XY colors and white values.
 
-In an ideal scenario, the MQTT device will have a state topic to publish state changes. If these messages are published with RETAIN flag, the MQTT light will receive an instant state update after subscription and will start with correct state. Otherwise, the initial state of the switch will be false/off.
+In an ideal scenario, the MQTT device will have a state topic to publish state changes. If these messages are published with a `RETAIN` flag, the MQTT light will receive an instant state update after subscription and will start with the correct state. Otherwise, the initial state of the switch will be `false` / `off`.
 
-When a state topic is not available, the light will work in optimistic mode. In this mode, the light will immediately change state after every command. Otherwise, the light will wait for state confirmation from device (message from `state_topic`).
+When a state topic is not available, the light will work in optimistic mode. In this mode, the light will immediately change state after every command. Otherwise, the light will wait for state confirmation from the device (message from `state_topic`).
 
-Optimistic mode can be forced, even if state topic is available. Try to enable it, if experiencing incorrect light operation.
+Optimistic mode can be forced, even if the `state_topic` is available. Try to enable it, if experiencing incorrect light operation.
 
 ```yaml
 # Example configuration.yml entry
@@ -61,7 +61,7 @@ Configuration variables:
 - **xy_value_template** (*Optional*): Defines a [template](/docs/configuration/templating/#processing-incoming-data) to extract the XY value.
 
 <p class='note warning'>
-  Make sure that your topics match exact. `some-topic/` and `some-topic` are different topics.
+  Make sure that your topics match exactly. `some-topic/` and `some-topic` are different topics.
 </p>
 
 <p class='note warning'>
@@ -83,7 +83,7 @@ Configuration variables:
 
 ## {% linkable_title Examples %}
 
-In this section you find some real life examples of how to use this sensor.
+In this section you will find some real life examples of how to use this sensor.
 
 ### {% linkable_title Brightness and RGB support %}
 

source/_components/lock.mqtt.markdown

@@ -13,9 +13,9 @@ ha_release: 0.15
 ha_iot_class: depends
 ---
 
-The `mqtt` lock platform let you control your MQTT enabled locks.
+The `mqtt` lock platform lets you control your MQTT enabled locks.
 
-In an ideal scenario, the MQTT device will have a `state_topic` to publish state changes. If these messages are published with `RETAIN` flag, the MQTT lock will receive an instant state update after subscription and will start with correct state. Otherwise, the initial state of the lock will be false/unlocked.
+In an ideal scenario, the MQTT device will have a `state_topic` to publish state changes. If these messages are published with a `RETAIN` flag, the MQTT lock will receive an instant state update after subscription and will start with correct state. Otherwise, the initial state of the lock will be `false` / unlocked.
 
 When a `state_topic` is not available, the lock will work in optimistic mode. In this mode, the lock will immediately change state after every command. Otherwise, the lock will wait for state confirmation from the device (message from `state_topic`).
 
@@ -43,12 +43,12 @@ Configuration variables:
 - **value_template** (*Optional*): Defines a [template](/docs/configuration/templating/#processing-incoming-data) to extract a value from the payload.
 
 <p class='note warning'>
-Make sure that your topic match exact. `some-topic/` and `some-topic` are different topics.
+Make sure that your topics match exactly. `some-topic/` and `some-topic` are different topics.
 </p>
 
 ## {% linkable_title Examples %}
 
-In this section you find some real life examples of how to use this lock.
+In this section you will find some real life examples of how to use this lock.
 
 ### {% linkable_title Full configuration %}
 

source/_components/notify.mqtt.markdown

@@ -12,7 +12,7 @@ ha_category: Notifications
 ha_iot_class: depends
 ---
 
-The MQTT notification support is different than the other [notification](/components/notify/) platforms. It is a service. This means that you don't have to create a configuration entry but you need to provide more details while calling the service.
+The MQTT notification support is different than the other [notification](/components/notify/) platforms. It is a service. This means that you don't have to create a configuration entry but you need to provide more details when calling the service.
 
 **Call Service** section from the **Developer Tools** allows you to send MQTT messages. Choose *mqtt/publish*  from the list of **Available services:** and enter something like the sample below into the **Service Data** field and hit **CALL SERVICE**.
 

source/_components/switch.mqtt.markdown

@@ -13,13 +13,13 @@ ha_release: 0.7
 ha_iot_class: depends
 ---
 
-The `mqtt` switch platform let you control your MQTT enabled switch.
+The `mqtt` switch platform lets you control your MQTT enabled switches.
 
-In an ideal scenario, the MQTT device will have a `state_topic` to publish state changes. If these messages are published with `RETAIN` flag, the MQTT switch will receive an instant state update after subscription and will start with correct state. Otherwise, the initial state of the switch will be false/off.
+In an ideal scenario, the MQTT device will have a `state_topic` to publish state changes. If these messages are published with a `RETAIN` flag, the MQTT switch will receive an instant state update after subscription, and will start with the correct state. Otherwise, the initial state of the switch will be `false` / `off`.
 
-When a `state_topic` is not available, the switch will work in optimistic mode. In this mode, the switch will immediately change state after every command. Otherwise, the switch will wait for state confirmation from device (message from `state_topic`).
+When a `state_topic` is not available, the switch will work in optimistic mode. In this mode, the switch will immediately change state after every command. Otherwise, the switch will wait for state confirmation from the device (message from `state_topic`).
 
-Optimistic mode can be forced, even if state topic is available. Try to enable it, if experiencing incorrect switch operation.
+Optimistic mode can be forced, even if the `state_topic` is available. Try to enable it, if experiencing incorrect switch operation.
 
 To enable this switch in your installation, add the following to your `configuration.yaml` file:
 
@@ -46,12 +46,12 @@ Configuration variables:
 - **value_template** (*Optional*): Defines a [template](/docs/configuration/templating/#processing-incoming-data) to extract a value from the payload.
 
 <p class='note warning'>
-Make sure that your topic match exact. `some-topic/` and `some-topic` are different topics.
+Make sure that your topic matches exactly. `some-topic/` and `some-topic` are different topics.
 </p>
 
 ## {% linkable_title Examples %}
 
-In this section you find some real life examples of how to use this sensor.
+In this section you will find some real life examples of how to use this sensor.
 
 ### {% linkable_title Full configuration %}
 

source/_components/vacuum.mqtt.markdown

@@ -12,7 +12,7 @@ ha_category: Vacuum
 ha_release: 0.54
 ---
 
-The `mqtt` component allows you to control your MQTT-enabled vacuum.
+The `mqtt` vacuum component allows you to control your MQTT-enabled vacuum.
 
 To add your MQTT vacuum to your installation, add the following to your `configuration.yaml` file: