[9.x] Add valet list command (laravel#8260)

* Add valet list command

* Update valet.md

Co-authored-by: Taylor Otwell <[email protected]>

Author: EvanGoss

valet.md

@@ -458,6 +458,7 @@ If you would like to define a custom Valet driver for a single application, crea
 
 Command  | Description
 ------------- | -------------
+`valet list` | Display a list of all Valet commands.
 `valet forget` | Run this command from a "parked" directory to remove it from the parked directory list.
 `valet log` | View a list of logs which are written by Valet's services.
 `valet paths` | View all of your "parked" paths.