Code documentation with Sphinx

[MerlinDEVILLARD]

Document all OpenHosta's functions with Sphinx and reStructuredText docstring. Make a Makefile rule to build the doc and put it in the workflow.

example

from typing import List

def exampleFunction(n:int, text:str)->List[str]:
    """
    Make a list of n time the text.

    :param n: The length of the final list
    :type n: int
    :param text: The string to be copied
    :type text: str
    :return: The list of length n containing text
    :rtype: List[str]
    """
    return