gitui: Add at v0.28.0

[lumi-me-not]

Summary

Adds a package for gitui

Test Plan

Built the package, installed it, committed using gitui. (so meta!)
Tests passed.

Checklist

• Recipe was built and tested against the volatile stream
• This change could gainfully be highlighted in the Stream Update notes once merged

[CLAassistant]

Thank you for your submission! We really appreciate it. Like many open source projects, we ask that you sign our Contributor License Agreement before we can accept your contribution.
_{You have signed the CLA already but the status is still pending? Let us recheck it.}

[ermo]

LGTM, thanks!

[lumi-me-not]

Would a DCO be good enough, rather than signing the CLA?

[ermo]

We are looking at the DCO vs. CLA thing internally, because we're not actually sure that the CLA is even legally enforcable. It was written by someone who is no longer active in the project.

[ermo]

@lumi-me-not For now, the CLA is mandatory.

Will that be a problem for you?

[lumi-me-not]

I would prefer not to sign any CLAs.

My apologies for not having noticed that there was a CLA before sending the PR.

[ermo]

I would prefer not to sign any CLAs.

My apologies for not having noticed that there was a CLA before sending the PR.

I don't suppose it will make a lot of difference, but the CLA text is here if you want to read it:

https://gist.github.com/ikeycode/788ff52526114f67a9bab3304f7f1134