Clarification on Github vs review.opendev.org

[fwiesel]

The contribution workflow is fairly generic.

But I see there are two options of contributing and unclear about, what the proper way is:

• Github Workflow (self-explanatory, since this repository resides on Github)
• Gerrit Workflow with review.opendev.org (more hidden, but there is a .gitreview)

I originally created PRs here, but then changed it to the gerrit workflow. I would appreciate if you could clarify the ambiguity. I can also provide a PR for the documentation, if needed. I just need to know what is the proper way.