fzf ripgrep integration (#1159)

Nushell has fuzzy autocompletion but in many areas fzf is still king and
has lot's of resources available.

This pr adds Ripgrep fzf integration, it basically reimplements the bash
version from [junegunn's
blog](https://junegunn.github.io/fzf/tips/ripgrep-integration/#wrap-up)
for nushell.

Author: FrancescElies

custom-completions/auto-generate/completions/fzf.nu

@@ -26,4 +26,26 @@ extern "fzf +s" [
 extern "fzf +m" [
 
 	...args
-]
+]
+
+# ripgrep->fzf->vim [QUERY]  https://junegunn.github.io/fzf/tips/ripgrep-integration/#wrap-up
+export def rg-fzf-nvim [] {
+    let RELOAD = 'rg --column --color=always --smart-case {q}'
+    let OPENER = '
+        if $env.FZF_SELECT_COUNT == 0 {
+            nvim {1} +{2}     # No selection. Open the current line in Vim.
+        } else {
+            nvim +cw -q {+f}  # Build quickfix list for the selected items.
+        }
+    '
+  ( fzf --disabled --ansi --multi
+      --bind $"start:reload:($RELOAD)" --bind $"change:reload:($RELOAD)"
+      --bind $"enter:become:($OPENER)" --bind $"ctrl-o:execute:($OPENER)"
+      --bind 'ctrl-a:select-all,ctrl-d:deselect-all,ctrl-/:toggle-preview'
+      --delimiter ':'
+      --preview 'bat --style=full --color=always --highlight-line {2} {1}'
+      --preview-window '~4,+{2}+4/3,<80(up)'
+      --query "$*" )
+}
+# ripgrep->fzf->vim [QUERY]
+export alias rfv = rg-fzf-nvim