Add cache list key example to help

pkg/cmd/cache/list/list.go

@@ -48,6 +48,9 @@ func NewCmdList(f *cmdutil.Factory, runF func(*ListOptions) error) *cobra.Comman
 
 		# List caches sorted by least recently accessed
 		$ gh cache list --sort last_accessed_at --order asc
+
+		# List caches with a prefix (or exact match)
+		$ gh cache list --key key-prefix
 		`),
 		Aliases: []string{"ls"},
 		Args:    cobra.NoArgs,