docs: added @since flag to cors option

Author: shakyShane

lib/default-config.js

@@ -242,10 +242,11 @@ module.exports = {
     browser: "default",
 
     /**
-     * Add HTTP access control (CORS) headers to assets served by Browsersync
+     * Add HTTP access control (CORS) headers to assets served by Browsersync.
      * @property cors
      * @type boolean
      * @default false
+     * @since 2.16.0
      */
     cors: false,