idea: Macro to make defining themes less repetitive

[tigerros]

I'm mostly talking about having to specify Cow::Borrowed for each string. The internal light and dark themes have 81 occurrences of the Cow::Borrowed and it will get larger. Adding new strings is annoying. Example solution:

pub const LIGHT_THEME: Theme = magic! {
  name: "light",
  // Could remove `foo: FooTheme` as well
  button: {
    background: %[str] "white",
    font_theme: {
      color: &[str] "black",
    }
  }
};