Github standard procedure. Submit issues if you find bugs. Clone, edit and create PR to submit patches.
The tip of master is kept at high quality. Changes may be committed directly to master but there are no force-pushes to this branch.
Sometimes half-finished work is committed to dev. This branch is unstable, may be rewritten at any time and might not even build. Eventually dev is taken to production quality and is merged into master.
Feature branches may be considered at a later stage if/when there is more than one contributor.