Refactor API structure: add internal handling, update templates, and remove deprecated files

public/html_loader.php

@@ -1,6 +1,6 @@
 <?php
 class HTMLLoader {
-    private $template;
+    private $page;
 
     function __construct() {
         // Check if Paths variables exists
@@ -20,7 +20,7 @@ class HTMLLoader {
         }elseif (!array_key_exists("error", $json)){
             die("Error Template was not found.");
         }
-        $this->template = $template;
+        $this->page = $template;
     }
 
     function showError($error) {