cleaned files by prefixing names with 'example' when not means to be used in other plugins aka not utils

plugins/wp_model_plugin/php/utils/add_to_front.php

@@ -5,8 +5,11 @@
 /*
  * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
 function that add the ajax script to front
-no need to check if already included, because $handle is uniq
-so it will not be recincluded, the first enqueued version will be kept
+needs to check if already included :
+- $handle is uniq so it will not be re-enqueued
+  the first enqueued version would be kept
+- but the vars add to front would be added twice
+  leading to js syntaxe error (redeclaraiton of 'let' or 'const')
 */
 function add_ajax_post() {
 	global $first_script;