added godoc (gopherjs#869)

pjebs · hajimehoshi · commit 0766667cb4d1 · 2018-10-17T21:02:53.000+09:00
diff --git a/README.md b/README.md
@@ -1,6 +1,7 @@
 GopherJS - A compiler from Go to JavaScript
 -------------------------------------------
 
+[![GoDoc](https://godoc.org/github.com/gopherjs/gopherjs/js?status.svg)](https://godoc.org/github.com/gopherjs/gopherjs/js)
 [![Sourcegraph](https://sourcegraph.com/github.com/gopherjs/gopherjs/-/badge.svg)](https://sourcegraph.com/github.com/gopherjs/gopherjs?badge)
 [![Circle CI](https://circleci.com/gh/gopherjs/gopherjs.svg?style=svg)](https://circleci.com/gh/gopherjs/gopherjs)
 
