First off, thank you for considering contributing to the project. It's people like you that helps in keeping this extension useful.
If you've noticed a bug or have a question, search the issue tracker to see if someone else in the community has already created a ticket. If not, go ahead and make one!
If this is something you think you can fix, then fork this repo and create a branch with a descriptive name.
A good branch name would be (where issue #325 is the ticket you're working on):
git checkout -b 325-add-new-feature
At this point, you should switch back to your master branch and make sure it's up to date with loopback4-s3's master branch:
git remote add upstream git@github.com:sourcefuse/loopback4-s3.git
git checkout master
git pull upstream master
Then update your feature branch from your local copy of master, and push it!
git checkout 325-add-new-feature
git rebase master
git push --set-upstream origin 325-add-new-feature
Finally, go to GitHub and make a Pull Request.
If a maintainer asks you to "rebase" your PR, they're saying that a lot of code has changed, and that you need to update your branch so it's easier to merge.
To learn more about rebasing in Git, there are a lot of good resources but here's the suggested workflow:
git checkout 325-add-new-feature
git pull --rebase upstream master
git push --force-with-lease 325-add-new-feature