Add Siti Delivery Time Notices plugin and related functionality

- Create main plugin file with metadata and initialization logic.
- Implement SitiDeliveryTimeNotice class for managing delivery time settings.
- Add JavaScript for updating delivery time notices on product pages.
- Update GitHub Actions workflow to reflect new file structure.
- Remove deprecated master-file.php.

siti-delivery-time-notices.php

@@ -0,0 +1,51 @@
+<?php
+/**
+ * Plugin Name:       Siti Delivery Time Notices
+ *
+ * @package           PluginPackage
+ * @author            Roberto Guagliardo | SitiWeb
+ * @copyright         2019 Roberto Guagliardo | SitiWeb
+ * @license           GPL-2.0-or-later
+ *
+ * @wordpress-plugin
+ * Plugin Name:       Siti Delivery Time Notices
+ * Plugin URI:        https://plugins.robert.ooo/plugin/
+ * Description:       A plugin to show delivery time notices on WooCommerce products.
+ * Version:           1.0.0
+ * Requires at least: 5.2
+ * Requires PHP:      7.2
+ * Author:            Roberto Guagliardo | SitiWeb
+ * Author URI:        https://sitiweb.nl/
+ * Text Domain:       siti-delivery-time-notices
+ * License:           GPL v2 or later
+ * License URI:       http://www.gnu.org/licenses/gpl-2.0.txt
+ */
+if ( ! defined( 'ABSPATH' ) ) {
+    exit;
+}
+
+define('SITI_DELIVERY_TIME_NOTICES_SLUG', 'siti-delivery-time-notices' );
+
+if ( ! defined( 'SITI_DELIVERY_TIME_NOTICES_VERSION' ) ) {
+	$plugin_data = get_file_data(
+		__FILE__,
+		[
+			'Version' => 'Version',
+		],
+		false
+	);
+
+	$plugin_version = isset( $plugin_data['Version'] ) && $plugin_data['Version'] ? $plugin_data['Version'] : '1.0.0';
+	define( 'SITI_DELIVERY_TIME_NOTICES_VERSION', $plugin_version );
+}
+
+if( ! class_exists( 'SitiWebUpdater2' ) ){
+	include_once( plugin_dir_path( __FILE__ ) . 'includes/SitiWebUpdater2.php' );
+}
+
+$updater = new SitiWebUpdater2( __FILE__ );
+$updater->set_owner( 'roberto' );
+$updater->set_repository( SITI_DELIVERY_TIME_NOTICES_SLUG );
+$updater->initialize();
+
+SitiDeliveryTimeNotice::init();