Update README.md - Ring 1.7 documentation link
| |*Resources*|*Operating System*|*Status*|
|---|---|---|---|
|Download |[![Download](http://ring-lang.sourceforge.net/binaryrelease.svg)](http://ring-lang.sourceforge.net/download.html)|**macOS (Compiler: gcc C)** |[![Build Status](https://travis-ci.org/ring-lang/ring.png)](https://travis-ci.org/ring-lang/ring)|
-|Help |[![Help](http://ring-lang.sourceforge.net/documentation.svg)](http://ring-lang.sourceforge.net/doc1.6/index.html)|**Ubuntu Linux (Compiler: gcc C)** |[![Build Status](https://travis-ci.org/ring-lang/ring.png)](https://travis-ci.org/ring-lang/ring)|
+|Help |[![Help](http://ring-lang.sourceforge.net/documentation.svg)](http://ring-lang.sourceforge.net/doc1.7/index.html)|**Ubuntu Linux (Compiler: gcc C)** |[![Build Status](https://travis-ci.org/ring-lang/ring.png)](https://travis-ci.org/ring-lang/ring)|
|Try |[![Try](http://ring-lang.sourceforge.net/interactive%20ring-use%20online-green.svg)](http://ring-lang.sourceforge.net/cgi-bin/ringlang.cgi)|**macOS (Compiler: clang C)** |[![Build Status](https://travis-ci.org/ring-lang/ring.png)](https://travis-ci.org/ring-lang/ring)|
|Support |[![Support](http://ring-lang.sourceforge.net/group-ask%20questions-yellowgreen.svg)](https://groups.google.com/forum/#!forum/ring-lang)|**Ubuntu Linux (Compiler: clang C)** |[![Build Status](https://travis-ci.org/ring-lang/ring.png)](https://travis-ci.org/ring-lang/ring)|
