add -c / --conf flag that use a configuration file

[Miou-zora]

Depends-on: #11 and #12

We only have CI/CD file in mirror or if we use -a we can add file or folder, but if we want to create a specific config for one type of project we actually can't. So, with -c / --conf flag, we sould add a configuration file.
The file will maybe be a .json file with some preset like;

{
    "add": ["include", "src", "tests", "Makefile", ".gitignore", ".gitattribute", "main.c"]
    "github-project": true
}