chore: update sass render script to work faster

[web-padawan]

No description provided.

[lkraav]

@web-padawan should I migrate my QA findings here, or you are picking them up from #17

[web-padawan]

@lkraav this PR is a copy of #17 and I now when it passed I will go ahead and merge it.
Let's continue sass-render discussion in #15 if you wish, or submit another PR.

[lkraav]

Oooh, I meant "picking them up from #17"

[web-padawan]

Agree about #17 (comment)
I will tweak this PR to exclude these internal files starting with _

[lkraav]

Also, info message about generated target output would be nice.

[web-padawan]

Updated the code and moved sass-render to separate package, also fixed few lint errors.

[lkraav]

@web-padawan maybe line capitalization was left a little bit inconsistent for messages. All sentence-case, perhaps?

/usr/bin/node /usr/lib/node_modules/yarn/bin/yarn.js run watch
yarn run v1.15.2
$ node scripts/watcher.js
watcher started!
saw change to packages/core/scss/button-base.scss
building styles
Processing packages/core/scss/button-base.scss

watcher build complete!

[web-padawan]

Sure, I will update it. Thanks, also noticed that yesterday while trying watcher.