Remove reference to Google groups in README (#2838)
Remove reference to Google groups in README (#2838)

Changing it with a link to the forums.
NativeScript/nativescript-cli,NativeScript/nativescript-cli,NativeScript/nativescript-cli,NathanaelA/nativescript-cli,NathanaelA/nativescript-cli,NathanaelA/nativescript-cli,NathanaelA/nativescript-cli,NativeScript/nativescript-cli