Add “:set relativenumber” option compatibility to vim keybindings moe

Describe your feature request
Currently, while in vim mode, executing “:set relativenumber” yields an error. In the normal vim editor, it changes line numbers to be relative to the current line (2 lines above and below the current both show “2” in the line number on the left). I’m hoping this could be added as a nice quality-of-life feature for vim users.

What problem(s) would this feature solve?
It would make using replit much more comfortable for vim users.

Explain what you were trying to do when you came across the problem leading to this feature request
I was setting up the replit environment on my iPad.