Added Stride notification component (#4921)

* Added Stride notification component

* ✏️ Implement configuration tags

source/_components/notify.stride.markdown

@@ -0,0 +1,63 @@
+---
+layout: page
+title: "Stride"
+description: "Instructions how to add Stride notifications to Home Assistant."
+date: 2018-03-14 15:00
+sidebar: true
+comments: false
+sharing: true
+footer: true
+logo: stride.png
+ha_category: Notifications
+ha_release: 0.66
+---
+
+The `stride` platform allows you to send notifications from Home Assistant to [Stride](https://stride.com/).
+
+You need to obtain a [Stride API token](https://developer.atlassian.com/cloud/stride/security/authentication/#using-room-tokens) to be able to send notifications. When creating the token, you'll see a section labeled "Use this conversation URL to post messages" - it will look something like "https://api.atlassian.com/site/55872e9f-047e-a619-b32c-19d37fbc6038/conversation/26c98c26-0ffd-a11e-3a55-1b397cb71fe0/message". The first set of numbers and letters (`55872e9f-047e-a619-b32c-19d37fbc6038`) is the Cloud ID, and the second set (`26c98c26-0ffd-a11e-3a55-1b397cb71fe0`) is the Room ID.
+
+To enable the Stride notification in your installation, add the following to your `configuration.yaml` file:
+
+```yaml
+# Example configuration.yaml entry
+notify:
+  - platform: stride
+    cloudid: CLOUD-ID
+    token: TOKEN
+    room: ROOM-ID
+```
+
+{% configuration %}
+name:
+  description: Setting the optional parameter `name` allows multiple notifiers to be created. The notifier will bind to the service `notify.NOTIFIER_NAME`.
+  required: false
+  default: notify
+  type: string
+cloudid:
+  description: The Stride Cloud ID to use for sending Stride notification.
+  required: true
+  type: string
+token:
+  description: The Stride API token to use for sending Stride notifications.
+  required: true
+  type: string
+room:
+  description: The default room to post to if no room is explicitly specified when sending the notification.
+  required: true
+  type: string
+panel:
+  description: Setting panel will override the default panel type (`None`) for the notification. By default not setting this will post to Stride without using a panel type. Valid options are 'None', 'info', 'note', 'tip', 'warning'.
+  required: false
+  type: string
+{% endconfiguration %}
+
+### {% linkable_title Stride service data %}
+
+The following attributes can be placed `data` for extended functionality.
+
+| Service data attribute | Optional | Description |
+| ---------------------- | -------- | ----------- |
+| `room`                 |      yes | (int) Same usage as in configuration.yaml. Overrides any setting set in configuration.yaml.
+| `panel`                |      yes | (str) Same usage as in configuration.yaml. Overrides any setting set in configuration.yaml.
+
+To use notifications, please see the [getting started with automation page](/getting-started/automation/).