Deprecate custom UI (#263)

docs/frontend_creating_custom_panels.md

@@ -18,21 +18,12 @@ The Home Assistant frontend will pass information to your panel by setting prope
 | -------- | ---- | -----------
 | hass     | object | Current state of Home Assistant
 | narrow   | boolean | if the panel should render in narrow mode
-| showMenu | boolean | if the sidebar is currently shown
 | panel    | object | Panel information. Config is available as `panel.config`.
 
 ## JavaScript versions
 
 The Home Assistant user interface is currently served to browsers in modern JavaScript and older JavaScript (ES5). The older version has a wider browser support but that comes at a cost of size and performance.
 
-To keep things easy, we advice you to tell your users to force the modern version of the frontend. That way you won't need any build tools while developing your panel. Add this to your config:
-
-```yaml
-# configuration.yaml example
-frontend:
-  javascript_version: latest
-```
-
 If you do need to run with ES5 support, you will need to load the ES5 custom elements adapter before defining your element:
 
 ```js

docs/frontend_creating_custom_ui.md

@@ -2,6 +2,8 @@
 title: "Creating custom UI"
 ---
 
+> This feature has been derepcated and is no longer supported. To add custom UI to Home Assistant, build a [custom Lovelace card](lovelace_custom_card.md) instead.
+
 ### State card
 
 If you would like to use your own [State card](frontend_add_card.md) without merging your code into [home-assistant-polymer](https://github.com/home-assistant/home-assistant-polymer/) you can create your own implementation.

website/sidebars.json

@@ -62,7 +62,6 @@
     ],
     "Custom UI": [
       "lovelace_custom_card",
-      "frontend_creating_custom_ui",
       "frontend_creating_custom_panels"
     ]
   },