AS-196: Remove documentation link (#53)

Removing documentation link due to: https://headspace.atlassian.net/browse/AS-196

CONTRIBUTING.md

@@ -7,13 +7,12 @@ welcomes contributions in the form of bug reports, feature requests, and pull re
 Here is a list of important resources for contributors:
 
 - [Source Code]
-- [Documentation]
+- Documentation
 - [Issue Tracker]
 - [Code of Conduct]
 
 [apache 2.0 license]: https://opensource.org/licenses/Apache-2.0
 [source code]: https://github.com/HeadspaceMeditation/transformer-embeddings
-[documentation]: https://transformer-embeddings.readthedocs.io/
 [issue tracker]: https://github.com/HeadspaceMeditation/transformer-embeddings/issues
 
 ## How to report a bug