Moved home-assistant scene to a scene.component.

Added powerview scene documentation.

source/_components/scene.home_assistant.markdown

@@ -0,0 +1,35 @@
+---
+layout: page
+title: "Scenes"
+description: "Instructions how to setup scenes within Home Assistant."
+date: 2015-03-23 19:59
+sidebar: true
+comments: false
+sharing: true
+footer: true
+logo: home-assistant.png
+ha_category: Organization
+---
+
+A user can create scenes that capture the states you want certain entities to be. For example a scene can contain that light A should be turned on and light B should be bright red.
+
+Scenes can be activated using the service `scene.turn_on`.
+
+```yaml
+# Example configuration.yaml entry
+scene:
+  - name: Romantic
+    entities:
+      light.tv_back_light: on
+      light.ceiling:
+        state: on
+        xy_color: [0.33, 0.66]
+        brightness: 200
+
+  - name: Movies
+    entities:
+      light.tv_back_light:
+        state: on
+        brightness: 100
+      light.ceiling: off
+```