Open-source made me a better developer, and can do the same for you.

TLDR;

This is our final stretch! We’ve navigated through building an Apps Script library, and now it’s time to discuss how you can contribute. Here’s a quick rundown of what we’ll cover:

1. GitHub Flow: Learn to fork the repository, create a feature branch, and make a pull request.
2. Guidelines: Tips on ensuring your pull request gets accepted.
3. Code of Conduct: We won’t delve into this, as respectful behavior is the default expectation.
4. License: Our library uses the MIT License, which is pretty much the one that lets you do anything you want with the code.
5. Issues: I will post issues that I consider a priority, but feel free to tackle any of them.
6. Process: Follow the steps outlined in our CONTRIBUTING.md file.

As a reminder, here are the links to the repo and the NPM page.

But first, let’s talk about what you should do before you open a pull request.

Source: Deploying an Apps Script Library Part 7: Contributing