Add different themes

[riccardovarenna]

It would be nice to have support for different themes in orgro.

Examples that come to mind is mainly the darkmode version of doom one.

doomthemes has many really cool looking ones.

[forgedOctopus]

An option for people with color deficiencies would also be nice.

I have a red-green color deficiency. In my case Orgro's default themes still work quite well, I only have troubles recognizing the comment color in code blocks in light-mode (to me it looks almost black).

In Emacs I use the since version 28 built-in modus-themes, which provide such an option (modus-themes-deuteranopia), which works very well for me.

However, I realize this is a very niche problem and color-deficiencies can vary a lot between individuals.

[amake]

The org_flutter library allows customizing colors; the main hurdle is making a UI for it that doesn't suck.

Incidentally the default colors are all taken from Emacs/Org Mode defaults.