feat(main): Add base theme: This is the falcon theme out of the box.

This is falcon v3.1.2

falcon/templates/errors/not-found.tpl

@@ -0,0 +1,46 @@
+{**
+ * Copyright since 2007 PrestaShop SA and Contributors
+ * PrestaShop is an International Registered Trademark & Property of PrestaShop SA
+ *
+ * NOTICE OF LICENSE
+ *
+ * This source file is subject to the Academic Free License 3.0 (AFL-3.0)
+ * that is bundled with this package in the file LICENSE.md.
+ * It is also available through the world-wide-web at this URL:
+ * https://opensource.org/licenses/AFL-3.0
+ * If you did not receive a copy of the license and are unable to
+ * obtain it through the world-wide-web, please send an email
+ * to license@prestashop.com so we can send you a copy immediately.
+ *
+ * DISCLAIMER
+ *
+ * Do not edit or add to this file if you wish to upgrade PrestaShop to newer
+ * versions in the future. If you wish to customize PrestaShop for your
+ * needs please refer to https://devdocs.prestashop.com/ for more information.
+ *
+ * @author    PrestaShop SA and Contributors <contact@prestashop.com>
+ * @copyright Since 2007 PrestaShop SA and Contributors
+ * @license   https://opensource.org/licenses/AFL-3.0 Academic Free License 3.0 (AFL-3.0)
+ *}
+<section id="content" class="page-content page-not-found">
+  {block name='page_content'}
+
+    {block name="error_content"}
+      {if isset($errorContent)}
+        {$errorContent nofilter}
+      {else}
+        <h4>{l s='This page could not be found' d='Shop.Theme.Global'}</h4>
+        <p>{l s='Try to search our catalog, you may find what you are looking for!' d='Shop.Theme.Global'}</p>
+      {/if}
+    {/block}
+
+    {block name='search'}
+      {hook h='displaySearch'}
+    {/block}
+
+    {block name='hook_not_found'}
+      {hook h='displayNotFound'}
+    {/block}
+
+  {/block}
+</section>