Everyone is very welcome to contribute on the codebase of Remix. Please reach us in Gitter in case of any queries.
Remix libraries work closely with Remix IDE. Each library has a readme to explain its application.
When you add a code in any library, please ensure you add related tests. You can visit here to test your changes by linking the remix libraries with Remix IDE.
Please conform to standard for code styles.
Please follow Github's standard model of making changes & submitting pull request which is very well explained here. Make sure your code works fine locally before submitting a pull request.