[docs] GitHub proxy admin guide and tsh reference

[greedy52]

related:

• GitHub proxy #48762

note that the guide for the old method is removed:

• https://goteleport.com/docs/admin-guides/management/guides/ssh-key-extensions/

[github-actions]

Amplify deployment status

Branch	Commit	Job ID	Status	Preview	Updated (UTC)
STeve/48762_docs	c665e78	8	✅SUCCEED	steve-48762-docs	2025-01-10 15:21:02

[ptgott]

I would make the title more descriptive about what the integration entails, e.g., "Manage GitHub Access with Teleport" (depending on what's accurate here).

[greedy52]

not sure what's a good name here. i've changed it to Git Access with GitHub as we don't manage access yet. we only proxying git commands. the manage access part will come at a later time for another feature.

[ptgott]

For me, "Git Access with GitHub" implies that we're allowing users to access git using some feature of GitHub, which leaves out Teleport. Maybe "Proxy Git Commands with Teleport" would be descriptive enough for now?

[greedy52]

ya, that's better. Though i do think we should include GitHub in the title since it's really a github integration. What What do you think about "Proxy Git Commands with Teleport for GitHub"? Is it too long?

[ptgott]

I think that's good!

[ravicious]

I allowed myself to run the images through ImageOptim to reduce their size. I also added @2x suffix to github-new-ca.png so that the docs render it as a high DPI screenshot.

[ravicious]

Well, changing the suffix didn't have any effect, as it seems that the new docs engine doesn't do anything with the prefix (cc @ptgott). Still, it's probably a good idea to have it anyway in case we decide to address high DPI screenshots.