Fix broken link in readme

Author: gabro

community-build/test/scala/dotty/communitybuild/readme.md

@@ -14,4 +14,4 @@ To add your project to the community build you can follow these steps:
 2. Open a PR against this repo that:
      - Adds your project as a new git submodule
        - `git submodule add https://github.com/lampepfl/XYZ.git community-build/community-projects/XYZ`
-     - Adds a test in [CommunityBuildTest.scala](https://github.com/lampepfl/dotty/blob/master/src/test/scala/dotty/community-build/src/test/scala/dotty/communitybuild/CommunityBuildTest.scala)
+     - Adds a test in [CommunityBuildTest.scala](https://github.com/lampepfl/dotty/blob/master/community-build/test/scala/dotty/communitybuild/CommunityBuildTest.scala)