Default locations for .vimrc

[jabirali]

Currently, the default locations VSCodeVim looks for a .vimrc is:

Path to a Vim configuration file. If unset, it will check for $HOME/.vscodevimrc, $HOME/.vimrc, $HOME/_vimrc, and $HOME/.config/nvim/init.vim, in that order.

I would suggest adding two more paths to that list:

1. Vim and Neovim both support $HOME/.vim/vimrc by default (this is a useful alternative to $HOME/.vimrc if you e.g. have some customizations in ~/.vim/after/ftplugin/*.vim instead of using autocommands);
2. Vim 9.1+ added support for the XDG-compliant $HOME/.config/vim/vimrc (similarly to Neovim).