Add initial docs for iframe panels

source/_components/panel_iframe.markdown

@@ -0,0 +1,39 @@
+---
+layout: page
+title: "Panel iFrame"
+description: "Instructions how to add iFrames in the frontend of Home Assistant."
+date: 2015-07-17 18:00
+sidebar: true
+comments: false
+sharing: true
+footer: true
+logo: home-assistant.png
+ha_category: Other
+ha_release: 0.25
+---
+
+
+The `panel_iframe` support allows you to add additional panels to your Home Assistant frontend. The panels are listed in the sidebar and can contain external resources like the web frontend of your router, your monitoring system, or your media server.
+
+To enable Panel iFrames in your installation, add the following to your `configuration.yaml` file:
+
+```yaml
+# Example configuration.yaml entry
+panel_iframe:
+  router:
+    title: 'Router'
+    icon: 'mdi:router-wireless'
+    url: 'http://192.168.1.1'
+  fridge:
+    title: 'Fridge'
+    icon: 'mdi:fridge'
+    url: 'http://192.168.1.5'
+```
+
+Configuration variables:
+
+- **[panael_name]** (*Required*): Name of the panel.
+  - **title** (*Required*): Friendly title for the panel. Will be used in the sidebar.
+  - **icon** (*Optional*): The API token of your bot.
+  - **url** (*Required*): The chat ID of your user.
+