Dispatcher camera for 0.40 (#2219)

* Create camera.dispatcher.markdown

* Update camera.dispatcher.markdown

Minor spelling fix.

* Update camera.dispatcher.markdown

source/_components/camera.dispatcher.markdown

@@ -0,0 +1,41 @@
+---
+layout: page
+title: "Dispatcher IP Camera"
+description: "Instructions how to integrate internal dispatcher cameras within Home Assistant."
+date: 2017-03-08 00:00
+sidebar: true
+comments: false
+sharing: true
+footer: true
+ha_category: Camera
+logo: camcorder.png
+ha_release: 0.40
+ha_iot_class: "depends"
+---
+
+<p class='note'>
+This platform is meant for developers only.
+</p>
+
+The `dispatcher` camera platform allows developers to create virtual camera's.
+
+You would normally not add this camera to your configuration directly but have it be discovered by one of the components that uses it.
+
+```yaml
+# Example configuration.yaml entry
+camera:
+  - platform: dispatcher
+    signal: name_of_dispatcher_signal
+```
+
+To update the image from another piece of code, run this from an async context:
+
+```python
+from homeassistant.helpers.dispatcher import async_dispatcher_send
+
+async_dispatcher_send(hass, 'name_of_dispatcher_signal', image_data)
+```
+
+Configuration variables:
+- **signal** (*Required*): The signal name of dispatcher signal they send image data to this camera.
+- **name** (*Optional*): This parameter allows you to override the name of your camera.