Make requested changes from FoG PR

[urwrstkn8mare]

I've tried to quickly do some of the essential requested changes in this PR. Some changes I haven't implemented I've put as TODOs in the README.md but I don't think they are necessary to merge with FriendsOfGalaxy's fork.

Summary of what I've done:

• Add INSTALL_MULTIMC.md and redirect to it to make it easier to install.
• Added some cool badges!!!!
• Updated GIF.
• More minor changes to README.md including adding TODOs.
• Simplify launch() function.
• Move prepare_local_size_context() logic to get_local_size().
• Update Authentication UI.
• Move util type stuff to utils folder.
• use with open().
• Return GameTime, not None in get_game_time().
• Update download() to use separate thread.

[urwrstkn8mare]

Sorry for all those commits and force-pushing. I had to rebase some stuff. You can go to the commits tab see the actual commits.

[TouwaStar]

Seems to work ok on my pc, will accept as soon as fog confirms

[urwrstkn8mare]

Once everything is confirmed, I'll up ver to 1.0.2. Then the PR should be merged.

Edit: or you can do it just a reminder that it's got to be upped cause I made some changes since 1.0.1