add new theme classic-dark

[rpetit3]

Hello!

Here's a new theme that is based off 'github-dark' to match Github's current Dark Mode.

We had a brief discussion (#462) and I realize the "github-dark" theme will be updated when Primer is updated. This made me think it might be useful to create a separate theme, so that changes to Primer or GitHub's Dark Mode won't affect the theme.

I named it dark-mood, and I'm not attached to it, so if you want to rename go for it!

Please let me know if anything else is needed.

Thank you!

Here's a screenshots, from my local build:

[jdanyow]

@rpetit3 I like the idea of keeping the original dark theme around for folks who don't want to adopt GitHub's official dark theme. I'll revisit this PR once Primer lands primer/css#1131.

What do you think of Classic Dark for the theme name?

[rpetit3]

Classic Dark works perfectly! I'll update the PR

[zsdycs]

@jdanyow

I think this "PR" can be merged.
It has been included in the Chinese version Beaudar.

[rpetit3]

Hi @jdanyow

If you have a moment, would love to get your thoughts.

Thank you!

[rpetit3]

@jdanyow - Please me know if anything is needed on my end.

[rpetit3]

@jdanyow I think I'm going to go ahead and abandon this PR.

Utterances is great cheers!