Add GitLab

[frankier]

This is the first part of #535

This was initially tool assisted with ChatGPT computer use, but it's had a full human pass.

I'm creating this as a draft pull request. @samumantha Any feedback before I finish off the rest?

[samumantha]

Thank you!

I would like to forward this request to @MaritJenssen .

She was interested in supporting this work and familiar with gitlab.

Also ping to @hemanadhan and @dianaiusan for awareness that this work is ongoing. Both are the potential future maintainers of this lesson.

[samumantha]

One general comment would be to please also add something on the new tab also to the instructor guide. Mention any potential pitfalls, which tab to choose for teaching, etc.

[MaritJenssen]

I think this looks good overall. But it is unclear to me how I can search for ingredients in the recipes (step 5). I could not figure out how to get to the "project search field". Maybe this can be made clearer before merging?