Bugfix/356 lint staged

[mob8607]

Pull request

Fixes lint-staged handling. I had to keep postcss and eslint with commonJS because they are not supported right now.
The upcoming release of eslint should support it (v9.0), but maybe we therefore need to update our config file: https://eslint.org/docs/latest/use/configure/configuration-files-new

PostCSS seems not to support it out of the box as far as I understood. Maybe we can have a look at that as well.
E.g: postcss/postcss#1773

Ticket

#356

Browser testing

• add files to git staged and run npm run lint-staged

Checklist

• I merged the current development branch (before testing)
• Added JSDoc and styleguide demo
• Tested all links in project relevant browsers
• Tested all links in different screen sizes
• Did run automated tests and linters
• Did assign ticket
• Double checked target branch

Review/Test checklist

• Did review code and documentation
• Tested all links in project relevant browsers
• Tested all links in different screen sizes
• Did check accessibility (Wave, only errors)
• Re-assign ticket to developer

[patric-eberle]

Looks good to me.