Add name of CG

Author: Peter Rushforth

CONTRIBUTING.md

@@ -1,6 +1,6 @@
-# @CommunityGroup@
+# @MapML@
 
-This repository is being used for work in the W3C @CommunityGroup@, governed by the [W3C Community License Agreement (CLA)](http://www.w3.org/community/about/agreements/cla/). To make substantive contributions, you must join the CG. 
+This repository is being used for work in the W3C @Maps4HTML@ Community Group, governed by the [W3C Community License Agreement (CLA)](http://www.w3.org/community/about/agreements/cla/). To make substantive contributions, you must join the CG. 
 
 If you are not the sole contributor to a contribution (pull request), please identify all 
 contributors in the pull request comment.
@@ -18,4 +18,4 @@ If you added a contributor by mistake, you can remove them in a comment with:
 ```
 
 If you are making a pull request on behalf of someone else but you had no part in designing the 
-feature, you can remove yourself with the above syntax.
+feature, you can remove yourself with the above syntax.