Update documentation links

Fixes #1299.

CONTRIBUTING.rst

@@ -14,7 +14,7 @@ Pull requests are great! We love them; here is a quick guide:
 
 - Before contributing make sure you check the docs. There are two versions of docs available:
 
-  + `latest`_, for use with the bleeding-edge GitHub version.
+  + `master`_, for use with the bleeding-edge GitHub version.
 
   + `stable`_, for use with the PyPI version.
 
@@ -118,6 +118,6 @@ http://contributor-covenant.org/version/1/1/0/.
 .. _Fork the Repo: https://help.github.com/articles/fork-a-repo/
 .. _Start Here: http://rogerdudler.github.io/git-guide/
 .. _good-first-bug: https://github.com/hylang/hy/issues?q=is%3Aissue+is%3Aopen+label%3Agood-first-bug
-.. _latest: http://hylang.org/
-.. _stable: http://docs.hylang.org/en/stable/
+.. _master: http://docs.hylang.org/en/master/
+.. _stable: http://hylang.org/
 

README.md

@@ -40,9 +40,10 @@ Project
 -------
 
 * Code: https://github.com/hylang/hy
-* Docs (latest, for use with bleeding-edge github version): http://hylang.org/
-* Docs (stable, for use with the PyPI version): http://docs.hylang.org/en/stable/
-* Quickstart: http://hylang.org/en/latest/quickstart.html
+* Documentation:
+  * stable, for use with the latest stable release: http://hylang.org/
+  * master, for use with the latest revision on GitHub: http://docs.hylang.org/en/master
+* Quickstart: http://hylang.org/en/stable/quickstart.html
 * Bug reports: We have no bugs! Your bugs are your own! (https://github.com/hylang/hy/issues)
 * License: MIT (Expat)
 * [Contributor Guidelines & Code of Conduct](https://github.com/hylang/hy/blob/master/CONTRIBUTING.rst)