Readme rewrite

Our readme.txt is outdated as hell, so I took it upon myself to rewrite it in Markdown. For the sake of simplicity, it links to the wiki for compile instructions. Feel free to commit to the readmerewrite branch if anything should be done differently.

Had significant input via IRC as it was being written.

No objections to having a readme rewrite (looks good to me as it is), though frankly our source code compiling wiki documentation isn't that up to scratch currently so I'm reserved about linking to it for compiling instructions.

Btw the build status part glitches a bit when the readme is viewed from here http://git.magicalgirl.moe/STJr/SRB2/blob/f1ab448442d9a8387634649de191c1be440b0cfa/README.md or here http://git.magicalgirl.moe/STJr/SRB2/tree/f1ab448442d9a8387634649de191c1be440b0cfa I suspect it may be to do with GitLab trying to treat the build status part as a header with ...apparently no name? May be worth looking into unless it's just GitLab's fault or something (if it is, then lol).

Ah I see, you put a bunch of "="s under the build status line, that's apparently alternative markdown for an H1-size header

Added 1 new commit:

• f9e01c2b - Fixed up markdown so the build status isn't treated as a header anywhere

Added 1 new commit:

• 86ccecc6 - Let's be more specific here

I suppose I can survive with the wiki link for now, and I've personally fixed the problems (see http://git.magicalgirl.moe/STJr/SRB2/blob/readmerewrite/README.md or http://git.magicalgirl.moe/STJr/SRB2/tree/readmerewrite for how it looks right now)

EDIT: https://github.com/STJr/SRB2/tree/readmerewrite GitHub is fine too it appears

Added 1 new commit:

• 0595325f - Make disclaimer H2 instead of H3

mentioned in commit 987c490b

Status changed to merged