updated CONTRIBUTING.md (#259)

added link to CLA form

CONTRIBUTING.md

@@ -2,12 +2,15 @@
 
 Please read these guidelines before contributing to ZendeskApi_v2:
 
+ - [CLA](#CLA)
  - [Question or Problem?](#question)
  - [Issues and Bugs](#issue)
  - [Feature Requests](#feature)
  - [Submitting a Pull Request](#pullrequest)
- - [Contributor License Agreement](#cla)
-
+ - [Contributor License Agreement](#readcla)
+
+## <a name="CLA"></a> Sign Contributor License Agreement
+ [Please sign the Contributor License Agreement][cla].
 
 ## <a name="question"></a> Got a Question or Problem?
 
@@ -57,7 +60,7 @@ they work
 Read [GitHub Help][pullrequesthelp] for more details about creating pull requests.
 
 
-## <a name="cla"></a> Contributor License Agreement
+## <a name="readcla"></a> Contributor License Agreement
 
 By contributing your code to ZendeskApi_v2 you grant Elizabeth Schneider a non-exclusive, irrevocable, worldwide,
 royalty-free, sublicenseable, transferable license under all of Your relevant intellectual property rights
@@ -81,7 +84,7 @@ you provide is on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND
 INCLUDING, WITHOUT LIMITATION, ANY WARRANTIES OR CONDITIONS OF TITLE, NON-INFRINGEMENT, MERCHANTABILITY, OR FITNESS
 FOR A PARTICULAR PURPOSE.
 
-
+[cla]: https://www.clahub.com/agreements/mozts2005/ZendeskApi_v2
 [github]: https://github.com/mozts2005/ZendeskApi_v2
 [stackoverflow]: http://stackoverflow.com/questions/tagged/zendeskapiv2
 [dropbox]: https://www.dropbox.com