Fix #1269 extract documentation

Fix #1271 Add description from docs on beego.me to README
and also add same description to godoc

doc.go

@@ -0,0 +1,17 @@
+/*
+beego: an open-source, high-performance, modular, full-stack web framework
+
+It is used for rapid development of RESTful APIs, web apps and backend services in Go.
+beego is inspired by Tornado, Sinatra and Flask with the added benefit of some Go-specific features such as interfaces and struct embedding.
+
+	package main
+	import "github.com/astaxie/beego"
+
+	func main() {
+	 beego.Run()
+	}
+
+more infomation: http://beego.me
+*/
+package beego
+