Moved constants to a file
Seems like a logical thing to do.
Updated README
[Project/Improve readme]
Merge branch 'master' into const-files
Merge remote-tracking branch 'origin/master'
Merge branch 'const-files'

Conflicts:
	src/main/groovy/io/github/nelsoncrosby/gridrace/GridRace.groovy
Added some random documentation
Merge branch 'const-files-actual'
Fixed a merge nightmare caused by mis-click.
It's now back at a sane point, I'll try and restore the changes I made.
Made constants exist in a file