[Feature] Add `Obsidian` file theme

[younisdev]

Summary

Recently Obsidian theme got introduced in #336. This issue aims to port the global Obsidian theme to the file theme registry.

To achieve this, you need to:

1. Add the theme entry in themes.json file referencing the CSS classes of the new theme.
2. Add your CSS classes in themes.css.

Additional Information:

• Check out modal registry for examples of the Obsidian theme:

  • modal themes.json.
  • modal themes.css.

• To test your changes:
  1 - Run

  npm install
  npm run dev

  2 - Add your theme name in the devbench file.jsx.

[nirupam-06]

Hi! I'd like to work on this issue. Could you please assign it to me? Thanks!

[younisdev]

Hi! I'd like to work on this issue. Could you please assign it to me? Thanks!

@nirupam-06 Sure, assigned!