Add a new `--create` cmake command

The new command will provide a minimalist CMake project initializer. It will set up a new project for only an executable at the moment.

I didn't invest much more time than the current minimalist approach, because I didn't know if it is something you would like to introduce. I can already see the possibility of introducing template projects for a library, header-only, FetchContent, etc.

I was thinking of maybe using template files instead of this fout style, but it looks like this is what is used around the codebase, so I just followed the current style without introducing more complex components.

I got this idea from playing with xmake and cargo; since those two had project initializers it was much quicker to get started and easy to experiment with. I was wondering why CMake didn't have one. There is plenty of other projects that do have their project generator.

There are 3rd party tools that can provide project initializers for CMake. Here is an example: https://pypi.org/project/cmake-init/. Maybe that's the way you want to continue which is completely fine.

On a final note, CMake is a meta-build system. If I want a project generator, maybe I should use a different tool ?