docs(readme) add link to DEVELOPER.md (#4596)

Marketionist · qiyigg · commit 1b486a2ff275 · 2017-11-22T14:22:08.000-08:00
diff --git a/README.md b/README.md
@@ -34,4 +34,4 @@ Please ask usage and debugging questions on [StackOverflow](http://stackoverflow
 
 For Contributors
 ----------------
-See DEVELOPER.md
+See [DEVELOPER.md](https://github.com/angular/protractor/blob/master/DEVELOPER.md)
