Add missing newline after runtests/debug

CONTRIBUTING.md

@@ -73,6 +73,7 @@ You can debug with VS Code or Node instead with `jake runtests debug=true`:
 ```Shell
 jake runtests tests=2dArrays debug=true
 ```
+
 ## Adding a Test
 To add a new testcase, simply place a `.ts` file in `tests\cases\compiler` containing code that exemplifies the bugfix or change you are making.