Summary:
There are a lot of outdated information like legacy links and inaccurate feature descriptions in the docs. There are also some style errors. This fixes these problems.

Type: skip

Test Plan: N/A

Reviewers: O1 the Kazv Project, nannanko

Reviewed By: O1 the Kazv Project, nannanko

Differential Revision: https://iron.lily-is.land/D134