feat: Add One Light and One Dark Themes

[mrousavy]

fixes: #218

[gksander]

Hi @mrousavy – thanks for contributing this. As an avid OneDark user, I really appreciate this 😄 I pulled down your branch and integrated the new themes into the demo, but most tokens seem to be getting colored with the hsl(220, 14%, 71%) line so things don't look quite right. I'm going to poke around a bit to see what it takes to get the additional colors in the right place.

[gksander]

Added a few tweaks to oneDark and oneLight:

And added a changeset record so we can release this into the wild once merged.

[carloskelly13]

Ran the demo, both look great. Thank you for adding these two new themes!

[gksander]

Okay, these changes should be live with version 2.1.0 🥳

[mrousavy]

Ah yeah I think I messed something up with the colors, my fault!!

I'll try with your changes in a second to double check if both themes look correct, orherwise I'll send another PR!

Thanks! :)