Neovim packer fzf config - apple silicon

- [x] I have fzf 0.30.0 or above
- [x] I have read through https://github.com/junegunn/fzf.vim/blob/master/README.md
- [x] I have read through https://github.com/junegunn/fzf/blob/master/README-VIM.md
- [x] I have read through the manual page of fzf (`man fzf`)
- [x] I have searched through the existing issues

Works with minimal version

```bash
vim -Nu <(curl https://gist.githubusercontent.com/junegunn/6936bf79fedd3a079aeb1dd2f3c81ef5/raw)
```

**issue:** ``:Rg`` does not work as fzf.vim doesn't find Rg

Issue comes from mac silicon installing fzf and rg under the following dirs when using ``brew install``
- ``/opt/homebrew/bin/fzf``
- ``/opt/homebrew/bin/rg``

```lua
return require("packer").startup(function(use)
-- Packer can manage itself
use("wbthomason/packer.nvim")

use("junegunn/fzf.vim")

end)
```
^ works for just ``:FZF``

How can I specify the Rg dir?