doc: fix recipe for async :Make

[Arniiiii]

Using recipe before:

QuickFix doesn't understand what is the place ( I checked via :cnext ), so parsing clearly does not work.

Using new recipe:

Solution heavily depends on solution from https://phelipetls.github.io/posts/async-make-in-nvim-with-lua/ and the fact that Neovim somehow understand by itself that if file is *.rs , then compiler is cargo and therefore sets corresponding errorformat .

[stevearc]

I think most of these changes are unnecessary. If you just replace this line with

errorformat = vim.o.errorformat

does that fix the behavior for you?