Resolve Stylelint conflicts with Prettier formatting

[luboskmetko]

Certain Prettier formatting of SCSS files produces linting errors in Stylelint. We should update related Stylelint rules

• indentation inside parentheses - Prettier indents 6 spaces, Stylelint expects 4
• selector-attribute-quotes - Prettier adds them, our config says never

[luboskmetko]

Indentation inside parentheses can be solved with

  indentation:
    - 2
    - indentInsideParens: twice

[luboskmetko]

Actually, better will be to ignore indentation inside parentheses, because Prettier too many variations.

  indentation:
    - 2
    - ignore: inside-parens