quick readme fix + new WebP and VGM patterns

[applecuckoo]

this PR is getting bigger and bigger as it is left unmerged, lol

Also, the VGM pattern should fix #180. There's no VGM test file as I'm not sure if there are any public domain/GPL v2 examples out there.

The Protobuf commits should fix #261 and fix #152.

[applecuckoo]

@WerWolv hey! Just a quick reminder ping to merge this and all the other PRs sitting around. Also, a couple of test file notes from me - I've made it tickable for ease of tracking:

• I haven't put in a VGM sample due to potential copyright pitholes and stuff. The stuff at Battle of the Bits seems to be mostly CC BY-NC-SA, so I can't use that, and the Furnace tracker demos are all rights reserved, so that's out of the picture as well.
• The protobuf test file is just full of zeros and doesn't really appear to be a 'real' protobuf wire, might be worth investigating

[WerWolv]

Thank you! Sorry for the huge delay...