home: vim: use 'exrc'

Remove the home-grown "solution" that I had stolen from school (and
never used...) for project-local configuration.

Since [1], it is okay to use the built-in vim option for this, since it
only asks for user-input before trusting a file.

Since [2] they even support lua files!

[1]: https://github.com/neovim/neovim/pull/20956
[2]: https://github.com/neovim/neovim/pull/21436

home/vim/init.vim

@@ -102,12 +102,10 @@ set ignorecase
 set smartcase
 " }}}
 
-" Import settings when inside a git repository {{{
+" Project-local settings {{{
 """""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""
-let git_settings=system("git config --get vim.settings")
-if strlen(git_settings)
-    exe "set" git_settings
-endif
+" Securely read `.nvim.lua` or `.nvimrc`.
+set exrc
 " }}}
 
 " vim: foldmethod=marker