feat: allow changing background colors

[Lexpeartha]

I think it would be really useful allowing others to modify background of the website, instead of hard-coding it to color.black in the css file

There already may be a good way to do this, in which case I think it would be good to mention this in the docs

Note: I tried creating my own main.css file to override docus' styles, but that didn't work for me

[Tahul]

Hey @Lexpeartha ; we should add that for sure!

Will do that in next release!

[Lexpeartha]

If you have any suggestions on how should API/changing of background look like, drop it here - I could make a PR

[bdrtsky]

@Lexpeartha thanks, I was planning to add additional related improvements for Docus tokenisation, that's why it's pending. Right now it needs to wait until Pinceau tokens.config HMR/restart issue is fixed. But if you want to make background specific update, then you can add docus.body.backgroundColor/docus.body.color tokens in tokens.config and move styles from main.css using this API

docus: {
  body: {
    backgroundColor: {
      initial: '',
      dark: ''
    }
  }
}