make coffee-script not a hard dep

since we compile JS before publishing anyway, coffeescript shouldn't
need to be installed for the bin to work.

if there was a better way to not load it when the JS is compiled, then
that would be nice...
get basic compliance with the editorconfig
basic syntax corrections
don't require/load all compilers

(when searching for the right file extension)
get rid of extraneous resolvePath function
get rid of --out arg