Document how to add C++ solvers and domains

[fteicht]

🚀 Feature

Write tutorial markdown files and C++ file generators to help algorithm designers implement C++ algorithms in scikit-decide, with associated Python wrapper classes.

Motivation

C++ algorithms can be more efficient than Python ones, yet adding C++ algorithms to scikit-decide that are accessible through the Python interface is not obvious (to say the least).

Pitch

Algorithm designers read tutorial markdown files.
They can also generate minimal C++and Python template files which they need to fill in when they want to add a new C++ algorithm or domain in scikit-decide.