docs: adjust various namings to reflect NAFF

[AstreaTSS]

What type of pull request is this?

• Non-breaking code change
• Breaking code change
• Documentation change/addition
• Tests change

Description

Just a bunch of renames that were needed with the NAFF rename.

Changes

• ...just look in the files changed. It's mostly docs changes, though there is one instance where a variable was changed (a constant referencing the repo). It's too minor to really note, though.
  • url="https://github.com/Discord-Snake-Pit/NAFF/tree/master/naff/ext/debug_extension" is invalid, I'm aware, but it will be soon:tm:.
  • For the "Getting Started" page, I did attempt a pun. Not the best, I'll admit, but it's there 😅.
  • Anything referencing the PyPI package or the Discord link wasn't changed, though they probably should be changed soon. Let me know if you want to add that here!

Checklist

• I've formatted my code with Black
• I've ensured my code works on Python 3.10.x
• I've tested my code