fix alert in kw completions (#878)

We update the code to add the alert function in the --alert subcommands

custom-completions/kw/kw-completions.nu

@@ -129,7 +129,7 @@ export extern "kw build" [
  --clean(-c) # Removes build files (keeps the configuration)
  --full-cleanup(-f) # Runs make distclean to reset the tree to the default state
  --cflags # Allow passing of flags to the compiler
- --alert: string
+ --alert: string@"nu-complete kw deploy alert" # set alert behaviour upon command completion
  --help(-h) # Shows help page
  --verbose # Verbose mode
 ]
@@ -385,7 +385,7 @@ export extern "kw vm" [
  --mount(-m) # This mounts the QEMU image in a specific directory, based on the data available in the kworkflow.config file. Only run this command after you turn off your VM.
  --umount(-n) # This unmounts the previously mounted QEMU image, based on the parameters available in the kworkflow.config file.
  --up(-u) # This starts the QEMU VM based on parameters in the kworkflow.config file.
- --alert: string   # Defines the alert behaviour upon the command completion. Options: s (sound notification), v (visual notification), sv or vs (both), n (or any other option) disables notifications.
+ --alert: string@"nu-complete kw deploy alert" # set alert behaviour upon command completion
 ]