MQTT switch config to integration key (#22837)

source/_integrations/switch.mqtt.markdown

@@ -22,11 +22,30 @@ To enable this switch in your installation, add the following to your `configura
 
 ```yaml
 # Example configuration.yaml entry
+mqtt:
+  switch:
+    - command_topic: "home/bedroom/switch1/set"
+```
+
+<a id='new_format'></a>
+
+{% details "Previous configuration format" %}
+
+The configuration format of manual configured MQTT items has changed.
+The old format that places configurations under the `switch` platform key
+should no longer be used and is deprecated.
+
+The above example shows the new and modern way,
+this is the previous/old example:
+
+```yaml
 switch:
   - platform: mqtt
     command_topic: "home/bedroom/switch1/set"
 ```
 
+{% enddetails %}
+
 {% configuration %}
 availability:
   description: A list of MQTT topics subscribed to receive availability (online/offline) updates. Must not be used together with `availability_topic`.
@@ -225,9 +244,9 @@ The example below shows a full configuration for a switch.
 
 ```yaml
 # Example configuration.yaml entry
-switch:
-  - platform: mqtt
-    unique_id: bedroom_switch
+mqtt:
+  switch:
+    - unique_id: bedroom_switch
       name: "Bedroom Switch"
       state_topic: "home/bedroom/switch1"
       command_topic: "home/bedroom/switch1/set"
@@ -262,9 +281,9 @@ The configuration will look like the example below:
 
 ```yaml
 # Example configuration.yaml entry
-switch:
-  - platform: mqtt
-    name: bathroom
+mqtt:
+  switch:
+    - name: bathroom
       state_topic: "home/bathroom/gpio/13"
       command_topic: "home/bathroom/gpio/13"
       payload_on: "1"