Add auto skin which honors the prefers-color-scheme media query

[sandervoerman]

This is a follow-up to #594, and adds the following changes:

• the auto skin renders in light or dark mode depending on the prefers-color-scheme media query;
• code has been refactored so that auto and classic share the same color definitions for light mode, and auto and dark for dark mode.

Screenshots:

auto skin, on Windows 10 in light mode:

auto skin, on Windows 10 in dark mode:

[ashmaroli]

Couple of comments:

• The name classic was selected to denote legacy appearance (Minima 2 n older). Having it switch to a dark mode doesn't sit nicely with me. How about --- auto, classic, dark..?
• The table details for the new variants include duplicate info. IMO, you could move that to an anchored section below the table and link to the section in the description cells.

[sandervoerman]

The name classic was selected to denote legacy appearance (Minima 2 n older). Having it switch to a dark mode doesn't sit nicely with me. How about --- auto, classic, dark..?

Sure! What would become the default skin, then? auto or classic?

[ashmaroli]

What would become the default skin, then? auto or classic?

classic for now since it is probably what consumers of this theme via jekyll-remote-theme plugin expects. Lets not shock them right away.

Once we come up with a way to demo the skins on every OS / browser, we may / can switch to auto being the default, or may not, at all. However, if we decide to cut a new release before that, it'll remain classic.
IMO, this shouldn't be a one-person decision.

[ashmaroli]

Um.. To reduce duplication or conflict from #594 getting merged before this, lets not make changes to the README on this branch just yet.. Let the document be finalized there first.

[sandervoerman]

ok sorry! 😅

[DoodlesEpic]

Closes #660
Any reason why this hasn't gotten any updates?

[sandervoerman]

Any reason why this hasn't gotten any updates?

I think this PR is waiting for #594 which in turn is waiting for review...

[mattr-]

#594 has been merged, so this PR can be updated against the lateest master and be moved out of draft mode when it's ready.

[sandervoerman]

@mattr- Ready now, let me know if you need anything else.

[mattr-]

@jekyllbot: merge +minor