fileserver: Add color-scheme meta tag

[kidonng]

Use <meta name="color-scheme"> to mark the page compatible with both light and dark themes, and let browser adapt to the themes as well.

Before:

After:

[mholt]

Thanks, I hadn't heard of this before.

PS. Are those screenshots from the latest on master? We have a new browse template. I'm sure it'll work fine for that too but might be worth checking :D

[kidonng]

Oops, should have clarified, the screenshots are taken with the latest release.

The meta tag just tells the brower to blend in, so it would likely to look fine if custom styles are well-made. But I agree it's worth checking.

[mholt]

Gotcha, yeah that should be fine then :) Thanks!