Remove CLA docs since it's not required by this project

Author: Daniel15

site/jekyll/dev/contributing.md

@@ -17,13 +17,6 @@ We actively welcome your pull requests on the
 
 If you don't have Visual Studio 2017, get the [community edition](https://visualstudio.microsoft.com/downloads/) (it's free!)
 
-## Contributor License Agreement ("CLA")
-
-In order to accept your pull request, we need you to submit a CLA. You only need
-to do this once to work on any of Facebook's open source projects.
-
-Complete your CLA here: <https://developers.facebook.com/opensource/cla>
-
 ## Issues
 
 We use GitHub issues to track public bugs. Please ensure your description is