bug: Incorrect Documentation Link in Web App

[renegadespork]

What happened?

The doc link for more information on "Third Party Instances" on the /login page is out of date.

It currently links to: https://developers.revolt.chat/faq/instances#what-is-a-third-party-instance

I believe it should link to: https://developers.revolt.chat/faq.html#admonition-what-can-i-do-with-revolt-and-how-do-i-self-host