add changelogs for version 2.0.0
The changelog for [Kommunicate-Android-Chat-SDK](https://github.com/Kommunicate-io/Kommunicate-Android-Chat-SDK). Also see the
[releases](https://github.com/Kommunicate-io/Kommunicate-Android-Chat-SDK/releases) on Github.
+## Kommunicate Android SDK 2.0.0
+1) Option to set custom prechat fields and validations
+2) Form type rich messge support with new rich message models
+3) Option to set some themes/colors dynamically from the dashboard
+4) Speech to text and textToSpeech feature
+6) Removed Contact and Phone releated permissions/code
+7) Several bug fixes and optimisations
+
## Kommunicate Android SDK 1.9.6
* Changed the CSAT rating scale to 1,5,10
* Show toast in case of APP_ID change
