Updated README.md

Now includes instructions on how to run and install Math Island
adding game map
Merge branch 'master' of https://github.com/liam-middlebrook/math-island
adding all the tile
Merge remote-tracking branch 'origin/dgonyeo-engine'
adding the pngs
Merge branch 'feature-player' of github.com:liam-middlebrook/math-island into dgonyeo-engine
Added a background, moved the game map
Didn't export the background correctly
Moved the map slightly
Forgot to change a thing
Tried to add fuel, cleaned up a thing
Merge remote-tracking branch 'origin/dgonyeo-engine' into feature-player