Syntax highlighting for source code in README.md

Markdown knows about golang, so use the source (formatting) luke

README.md

@@ -15,17 +15,17 @@ old `go1` API.
 ### Using the framework
 
 Synopsis:
+```go
+package main
 
-	package main
-
-	import (
+import (
 	"crypto/tls"
 	"fmt"
 
 	irc "github.com/fluffle/goirc/client"
-	)
+)
 
-	func main() {
+func main() {
 	// Creating a simple IRC client is simple.
 	c := irc.SimpleClient("nick")
 
@@ -61,7 +61,8 @@ Synopsis:
 
 	// Wait for disconnect
 	<-quit
-	}
+}
+```
 
 The test client provides a good (if basic) example of how to use the framework.
 Reading `client/handlers.go` gives a more in-depth look at how handlers can be