Slight Tweaks to the Forum layout

Recently changed the forum layout a little by:

- Changing the names of some forum categories
- Moved assorted forum subsections around into different forum categories
- A few forum subsections had their titles altered

Twitch has dropped MuGEN as an official game, and there for there was a tweak needed to the "Video Content Creation Reference" portal.

It now only links to (with regards to going off-site):

- Active streams on Twitch (looks differently than before as well)
- Most recent Mugen video uploads to YouTube

There is also a link to a forum section where people can promote their channel in a dedicated forum section to such.