If you want to continue work on a plugin which already exists in a repository, you can pull it into your environment by cloning it from the repository.
Make sure to install your composer dependencies and update your database after pulling the repo.
$ git clone https://github.com/codefarma/mwp-rules
$ cd mwp-rules
$ composer install
$ wp plugin activate mwp-rules
$ wp mwp update-database mwp-rules