Add fennec init function to initialize project configuration

[azjezz]

Fennec has the ability to work without any configurations, but it is always better to have explicit configurations.

The command should ask the user what files/directories to include, and what plugins to enable for the linter.

It would be good to take composer.json into account an automatically create configurations based on it ( i.e by using autoload directories, vendor-dir, and taking what frameworks are installed into account to know what plugins to enable, for example, symfony plugin when symfony framework is used ).