Type of node-sass package

[the-homeless-god]

Currently, node-sass has been marked as 'optional" dependency in package.json, but there are a few issues:

• rollup-plugin-scss can't work without node-sass
• project can't use installation like npm install --no-optional because rollup-plugin-scss will throws issues about missing of node-sass

Also some packages were deprecated

[thgh]

1. It can, using the sass package which does not require binaries
2. Woops, the readme should be updated to indicate that node-sass should be installed specifically.

[sirikon]

I would suggest to not include node-sass as an optional dependency and always require to specify the preferred sass package in package.json.

Currently want to use the plugin with sass (dart-sass) but node-sass gets installed anyway.

[thgh]

Let's do that for v3, PR welcome!

[FlorianWendelborn]

Thanks for fixing this. This simple change sped-up our install time in a medium-size monorepo by 70%: 3YOURMIND/kotti#403