[Block] Add separator color option #29
Description
Now that I've explored adding custom color options more in depth and found a good solution for allowing theme authors to customize those colors while respecting user settings (see X3P0: Progress for an example), I think it's worth adding a separator color option for the Breadcrumbs block.
Plus, theme authors can already set this via settings.custom.x3p0/breadcrumbs.color.separator in their theme.json. This should be exposed as a user option, too.