Add (composer): Add gtm library

config/googletagmanager.php

@@ -0,0 +1,27 @@
+<?php
+
+return [
+
+    /*
+     * The Google Tag Manager id, should be a code that looks something like "gtm-xxxx".
+     */
+    'id' => env('GOOGLE_TAG_MANAGER_ID', ''),
+    
+    /*
+     * Enable or disable script rendering. Useful for local development.
+     */
+    'enabled' => env('GOOGLE_TAG_MANAGER_ENABLED', true),
+
+    /*
+     * If you want to use some macro's you 'll probably store them
+     * in a dedicated file. You can optionally define the path
+     * to that file here and we will load it for you.
+     */
+    'macroPath' => env('GOOGLE_TAG_MANAGER_MACRO_PATH', ''),
+
+    /*
+     * The key under which data is saved to the session with flash.
+     */
+    'sessionKey' => env('GOOGLE_TAG_MANAGER_SESSION_KEY', '_googleTagManager'),
+
+];