I'm really glad you're reading this, because we need developers to help this project stay alive!
Please open a Pull Request with a clear list of what you've done (read more about pull requests). Please make sure all of your commits are atomic (one feature per commit).
Always write a clear log message for your commits. One-line messages are fine for small changes, but bigger changes should look like this:
$ git commit -m "A brief summary of the commit
>
> A paragraph describing what changed and its impact."
- This is open source software. Consider the people who will read your code, and make it look nice for them. It's sort of like driving a car: Perhaps you love doing donuts when you're alone, but with passengers the goal is to make the ride as smooth as possible.
There isn't any other particular guideline, feel free to contribute! Thanks!