We keep our issues on github fresh and clean. We put there feature requests, bugs, etc. If you want to help in developing our project - do it!
There are plenty of issues reported on github. Find one that suits you and make your change! Just rembember that...
Choose an issue you want to work on and assign yourself to it. Thanks to this, other contributors will know that someone is already working on it. Remember to assign yourself only when you truly have time dedicated to resolve the issue. If we don't see any PRs from you for an extended period of time, you'll likely be unassigned from the issue. Of course, feel free to reassign yourself to the same issue as soon as you find more time.
Our backlog is diverse. It has both cosmetic and functional changes. We try to prioritise them. Be prepared that issues without priority set can wait for their turn longer than you'd like it.
Best way to make sure your code will make to next release? Check if issue has milestone set and it's the closes one.
We write unit tests for our code, so make sure that your code is tested.
If your PR is not passing our tests then it won't be allowed to get to our precious code. No one will even review it.
Simple math here. If your PR contains only tests which makes our code more bug-resistant, then you can treat your code as if it had the highest priority.