Fix hard-to-read text on campaign and training page in frontend at October 31
The text was yellow against a white background (the moon in the Halloween background).
This is fixed by darkening the critical area.
Directory for automated tests to test the engine.
Run `ctest` in the root directory of this repository to run all tests.
Run `ctest -R <test name>` to run only the test with the given name.
This requires you to have CMake.