Rename the `CMake` folder

I use the cmdline a lot, and whenever I tab to try to auto complete `CMakeLists.txt` it stops at `CMake` thanks to this folder

Rename it, it contains toolchain files used to cross compile for the Raspberry Pi

This will probably also require you to update the paths in the `pi-cross-compile` pipeline task. It will also require you to modify the `build_docker` scripts and test them, so download WSL and Docker to verify that they still work.