Update README.md
Merge pull request #59 from iamaziz/master

Update README.md
Add RFCs docset
Processed docsets/RFCs/RFCs.tgz
SDL 2.0 Docset (version 2.0.3)
Processed docsets/SDL/org.libsdl.sdl20.docset.tgz
Rename SDL
Box2D Docset (version 2.3.1)
Processed docsets/Box2D/org.box2d.docset.tgz
Add uWSGI 2.0 docset