✨ Editor/Terminal Color Themes #189

Let's create our own set of pre-bundled themes.

• We can provide similar ones to what Xcode comes with along with a few of our own.
• Each theme will have the option to have a light mode and a dark mode that can optionally change when the user switches light/dark mode.
• We will have a setting to use the themes background, or use the standard window background which is tinted by your wallpaper.
• We can also provide "smart themes" which generate a theme based on the users tint color (See ✨ Automatically Generated Color Themes based on window tint color #46)
• We might leverage some work being done in 👀 Extension Architecture / API #76.

Related issue #187.

Questions

• Will themes each be extensions like in VSCode or will they be separate from themes in some way?