GitHub Sensor (#7942)

* 📚 Add GitHub sensor component docs

* 🔨 Clarify name

* 🔨 Fix typo and reword

* 🔨 Set optionals

* 📚 Add examples for both login methods

* 🔨 fix grammar

Co-Authored-By: timmo001 <contact@timmo.xyz>

* 🔨 remove optionals from example

* 📚 Reword setup section

Co-Authored-By: timmo001 <contact@timmo.xyz>

* ✨ Add enterprise server_url docs

* 🔨 Update release number

* 📚 Update HA Release

* 🔨 Change from server_url to url as suggested in main PR

* 🔨 Update docs to match changes to sensor

* 🔨 Update version

source/_components/sensor.github.markdown

@@ -0,0 +1,57 @@
+---
+layout: page
+title: "GitHub Sensor"
+description: "How to integrate the GitHub sensor into Home Assistant."
+date: 2018-12-24 18:00
+sidebar: true
+comments: false
+sharing: true
+footer: true
+logo: github.png
+ha_category: Sensor
+ha_release: 0.88
+ha_iot_class: "Cloud Polling"
+---
+
+The GitHub sensor integrates data from [GitHub](https://github.com/) to monitor your favorite repositories.
+
+## {% linkable_title Setup %}
+
+To set up this sensor you will need a [personal access token][accesstoken]. You will need to check the `repo` scope for the sensor to function.
+
+## {% linkable_title Configuration %}
+
+To enable this platform, add the following to your `configuration.yaml` file:
+
+```yaml
+# Example configuration.yaml entry
+sensor:
+  - platform: github
+    access_token: !secret github_access_token
+    repositories:
+      - path: 'home-assistant/home-assistant'
+```
+
+{% configuration %}
+access_token:
+  description: Your GitHub Access Token
+  required: true
+  type: string
+url:
+  description: If you are using a GitHub Enterprise server, add it's URL here. For example, `https://mygithubserver.com`
+  required: false
+  type: string
+repositories:
+  description: A list of repository paths and optionally a name
+  required: true
+  type: list
+  keys:
+    path:
+      description: Path to the repository. For Home Assistant this will be `home-assistant/home-assistant`
+      required: true
+      type: string
+    name:
+      description: Name of the sensor. Gives the sensor a custom name in Home Assistant. Defaults to the repository name from GitHub if not specified.
+      required: false
+      type: string
+{% endconfiguration %}