added sourcemap support

that’s not how i think those options work.

i think it should be `options.sourcemap && !options.sourcemap.inline` (“not inline” instead of “yes comment”)

why would you only write a file if the “add a comment” option is true?

e.g. if i want “no sourcemap comment, but an external .css.map file”, i’d do `options: {comment: false, inline: false}`.