Remove README.md "Contribute" link as the target doesn't exist (#2015)

Author: PeterDaveHello

README.md

@@ -74,7 +74,7 @@ How to use these files, as well as how to verify their signatures, are documente
 
 ### Code Contributors
 
-This project exists thanks to all the people who contribute. [[Contribute](CONTRIBUTING.md)].
+This project exists thanks to all the people who contribute.
 <a href="https://github.com/dnscrypt/dnscrypt-proxy/graphs/contributors"><img src="https://opencollective.com/dnscrypt/contributors.svg?width=890&button=false" /></a>
 
 ### Financial Contributors