Add some more Markdown annotations.

README.md

@@ -1,4 +1,6 @@
-Go support for Protocol Buffers - Google's data interchange format
+# Go support for Protocol Buffers
+
+Google's data interchange format.
 Copyright 2010 The Go Authors.
 https://github.com/golang/protobuf
 
@@ -20,8 +22,7 @@ To use this software, you must:
   for details or, if you are using gccgo, follow the instructions at
 	https://golang.org/doc/install/gccgo
 - Grab the code from the repository and install the proto package.
-  The simplest way is to run
-	go get -u github.com/golang/protobuf/{proto,protoc-gen-go}
+  The simplest way is to run `go get -u github.com/golang/protobuf/{proto,protoc-gen-go}`.
   The compiler plugin, protoc-gen-go, will be installed in $GOBIN,
   defaulting to $GOPATH/bin.  It must be in your $PATH for the protocol
   compiler, protoc, to find it.
@@ -102,6 +103,7 @@ for a protocol buffer variable v:
 
 Consider file test.proto, containing
 
+```proto
 	package example;
 	
 	enum FOO { X = 17; };
@@ -114,9 +116,11 @@ Consider file test.proto, containing
 	    required string RequiredField = 5;
 	  }
 	}
+```
 
 To create and play with a Test object from the example package,
 
+```go
 	package main
 
 	import (
@@ -149,7 +153,7 @@ To create and play with a Test object from the example package,
 		}
 		// etc.
 	}
-
+```
 
 ## Parameters ##