This option gathers basic Vim options into a single place. The idea is
to allow many options without making the Home Manager documentation
too verbose.
This also deprecates the options `programs.vim.lineNumbers` and
`programs.vim.tabSize`.
Fixes#69.
The intention is for the `xsession.windowManager` option to be
available for full modules in the future. The option
`xsession.windowManager.command` should now be used to specify the
window manager startup command.
Same motivation as in https://github.com/NixOS/nixpkgs/pull/28378.
zsh.initExtra parameter can be used by external modules which can
redefine user aliases. This change will give user-defined aliases
the highest priority.
