Update README.md

Added link to golang/protobuf repo

README.md

@@ -66,10 +66,9 @@ While protocol buffers have been available for open source users for some
 time, our examples use a new flavour of protocol buffers called proto3,
 which has a slightly simplified syntax, some useful new features, and supports
 lots more languages. This is currently available as an alpha release in
-Java, C++ from [the protocol buffers Github
+Java, C++, Java_nano (Android Java), Python, and Ruby from [the protocol buffers Github
 repo](https://github.com/google/protobuf/releases), as well as a Go language
-generator [wherever that is](), with more languages in development. Full
-documentation for proto3 is currently in development but you can see
+generator from [the golang/protobuf Github repo](https://github.com/golang/protobuf), with more languages in development. Full documentation for proto3 is currently in development, but you can see
 the major differences from the current default version in the [release notes](https://github.com/google/protobuf/releases).
 
 In general, we recommend that you use proto3 with gRPC as it lets you use the