fix: find workaround for Sass imports

[nicholaschiang]

We still need to find a workaround for @use-ing @material's Sass modules as detailed in this issue.

[nicholaschiang]

Actually, after a deeper dive into #11063 it looks like I implemented my configuration incorrectly (you guys seriously have to work on your documentation). This next.config.js seems to be working:

const path = require('path');

module.exports = {
  experimental: {
    sassOptions: {
      includePaths: [path.resolve(__dirname, 'node_modules')],
    },
  },
};

I'm going to keep this issue open but now I'm only asking for improved documentation for how to use/enable experimental features. You should also consider adding documentation to your website for such experimental features so that developers don't have to spend days searching through old issues, discussions, and PRs.

See this issue and this PR for more info.