Adding a link to documentation.

And a few other small readme changes.

README.md

@@ -1,5 +1,16 @@
-gRPC-Go: a Go implementation of gRPC, Google's RPC library
+#gRPC-Go
+
+The Go implementation of [gRPC](https://github.com/grpc/grpc)
+
+Installation
+------------
 
 To install this package, you need to install Go 1.4 and setup your Go workspace on your computer. The simplest way to install the library is to run:
 
-go get google.golang.org/grpc
+```
+$ go get google.golang.org/grpc
+```
+
+Documentation
+-------------
+You can find more detailed documentation and examples in the [grpc-common repository](http://github.com/grpc/grpc-common).