Allow further customization of the "Code" macro in the new editor. The "Code" macro replaced "Code Block" macro, but it does not allow as many customization options as the macro it replaced.
Currently, the "Code" macro replaced the "Code Block" macro in the new editor, but this new macro won't provide users with much customization options (just its width) as much as the old macro did. This includes:
Change the background color (theme)