Fixing URLs in documentation
Fixing URLs in documentation

Fixing references to GreenGroup on github to now be ReactionMechanismGenerator
enochd/RMG-Py,chatelak/RMG-Py,nickvandewiele/RMG-Py,nyee/RMG-Py,enochd/RMG-Py,chatelak/RMG-Py,pierrelb/RMG-Py,pierrelb/RMG-Py,nickvandewiele/RMG-Py,nyee/RMG-Py