Contributions to awesome-cs-education is done through GitHub pull requests. You can do this in the traditional way of forking the repo, editing files in your copy of the repo and then issuing a pull request.
If you’re not familiar with making pull requests you can submit changes right from the awesome-cs-education repo.
First, go to the awesome-cs-education repo at https://github.com/zamansky/awesome-cs-education.
Next, click on the README.org file - that’s where the list lives.
The list is written using org-mode markup. It’s pretty straightforward. Here’s a cheatsheet: http://ergoemacs.org/emacs/emacs_org_markup.html.
Then click on the edit icon:
and make the changes.
Finally, fill out the section on the bottom and propose the changes: