The instructions below explain how to make improvements to existing Dataform packages. You may also find it useful to read GitHub's guide on forking projects.
The first step is to fork the repository of the package. In GitHub, the fork option is in the top-right corner when you have the repository page open.
To make changes to the forked repo, you'll need to create a clone and make the changes in a branch. You can either create a clone of the repo on your desktop, or create a new Dataform Web project and link the new project to the repo from the project settings page.
Once you've cloned the repo (either on your desktop or in Dataform Web), you can create a branch. Make changes in the branch, and once you're ready, push the branch back up to the forked repo in GitHub.
Open the repository on GitHub.com, and you'll see a banner prompting you to submit the branch "upstream". This will take you to the pull request creation page. Try and add as much detal as posisble to the pull request, to help the reviewer.
Add a reviewer to the PR and submit it. The reviewer will now work with you on preparing the PR to be accepted into the package.
On behalf of the Dataform community, thanks in advance for your contribution!