WIP Command list (to resolve #33)

Soul-crushing diff, sorry. Breaks out our commands to separate files, but takes away our aliased commands `create`, `g`, `scaffold`, `serve`. Need to figure out how best to implement those. Opening this now for moar eyes.
I guess we should add it to the JS style checker, but I think most of Moz (myself included) prefers to keep even single-line blocks on their own line, for future reference. Makes things a bit easier to scan.