Currently, Doxygen docs are compiled in source instead of output to the build folder.
By integrating with CMake we can output docs as part of the build.
We can also choose which modules we want to generate documentation for instead of making it hardcoded.

Note this patch is only a proof of concept and needs to be updated to use update CMake syntax

A similar approach can be used for python API docs so we can generate python API docs as part of the build process.

Resources

https://cmake.org/cmake/help/latest/module/FindDoxygen.html
https://devblogs.microsoft.com/cppblog/clear-functional-c-documentation-with-sphinx-breathe-doxygen-cmake/