Fix name of group in CONTRIBUTING.md.

CONTRIBUTING.md

@@ -1,19 +1,18 @@
-# Credentials Community Group
+# Verifiable Credentials Working Group
 
 Contributions to this repository are intended to become part of
 Recommendation-track documents governed by the
 [W3C Patent Policy](https://www.w3.org/Consortium/Patent-Policy-20040205/) and
 [Software and Document License](https://www.w3.org/Consortium/Legal/copyright-software).
-
-To make substantive contributions to specifications, you must either
-participate in the relevant W3C Working Group or make a non-member patent
-licensing commitment.
+To make substantive contributions to specifications, you must either participate
+in the relevant W3C Working Group or make a non-member patent licensing
+commitment.
 
 If you are not the sole contributor to a contribution (pull request), please
-identify all contributors in the pull request comment.
+identify all  contributors in the pull request comment.
 
-To add a contributor (other than yourself, that's automatic), mark them one
-per line as follows:
+To add a contributor (other than yourself, that's automatic), mark them one per
+line as follows:
 
 ```
 +@github_username