Add deprecation notice / ceasing active development
Active development officially ceased Sept 20th.
+**The blockly-android project is _no longer actively developed_ by the
+Google Blockly team. We will continue to review and accept pull requests.
+If you are looking to create a new Blockly-based app, we recommend using
+the [web version](http://github.com/google/blockly) in a WebView. We
+have also create an
+[Android Studio demonstration project](https://github.com/google/blockly/tree/develop/demos/mobile/android)
+that does exactly this.**
+
[Blockly][1] is a library for building drag-and-drop visual editors for
JavaScript and other programming languages. [Blockly for Android][2] is
a developer preview of Blockly's editor built with standard Android
