Beside absolute numbering vim can display additional column with line numbering relative to current cursor postion.
Vim doesn't have `unset` function. To turn off an option vim uses "no" prefix.
This adds a readonly package option which will be set to the resulting configured vim package, so it can be refered to by other configuration. An example would be home.sessionVariables.EDITOR = config.programs.vim.package + "/bin/vim".
