all: Fix minor typos

tpl/urls/urls.go

@@ -141,7 +141,7 @@ func (ns *Namespace) refArgsToMap(args interface{}) (map[string]interface{}, err
 		return m, nil
 	case []string:
 		if len(v) == 0 || len(v) > 2 {
-			return nil, fmt.Errorf("invalid numer of arguments to ref")
+			return nil, fmt.Errorf("invalid number of arguments to ref")
 		}
 		// These where the options before we introduced the map type:
 		s = v[0]