docs: mention admin token requirement in --all-projects flag description

Author: abhijith-darshan

cmd/webhook/main.go

@@ -24,7 +24,7 @@ func main() {
 	var domainFilters []string
 	var allProjects bool
 	pflag.StringArrayVar(&domainFilters, "domain-filter", []string{}, "List of domains to work on (can be specified multiple times)")
-	pflag.BoolVar(&allProjects, "all-projects", false, "Manage all zones and recordsets regardless of the project the service user resides in")
+	pflag.BoolVar(&allProjects, "all-projects", false, "Manage all zones and recordsets regardless of the project the service user resides in (requires an admin or appropriately scoped token)")
 	pflag.Parse()
 
 	log.SetLevel(log.DebugLevel)