shell: nushell integration scripts (#4630)

Co-authored-by: imsys <911254+imsys@users.noreply.github.com>
Co-authored-by: Grzegorz Zalewski (Greg) <12560152+zalewskigrzegorz@users.noreply.github.com>
Co-authored-by: René Jochum <rene@jochum.dev>
Co-authored-by: Junegunn Choi <junegunn.c@gmail.com>
Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com>

man/man1/fzf.1

@@ -1373,6 +1373,12 @@ Print script to set up Fish shell integration
 
 e.g. \fBfzf \-\-fish | source\fR
 
+.TP
+.B "\-\-nushell"
+Print script to set up Nushell shell integration
+
+e.g. \fBfzf \-\-nushell | save \-f ~/.config/nushell/autoload/_fzf_integration.nu\fR
+
 .SS OTHERS
 .TP
 .B "\-\-no\-mouse"