refactor(vim): switch to more minimal heredoc syntax
refactor(vim): switch to more minimal heredoc syntax

The `HERE` is ugly, IMO.

See `:h lua-heredoc`.

wincent/wincent,wincent/wincent,wincent/wincent,wincent/wincent,wincent/wincent,wincent/wincent,wincent/wincent,wincent/wincent