Updates twig configuration example to match current offering

Updates the twig configuration example to add the following, which are also available:

- autoescape
- optimizations
- runtime_loaders
- timezone

Author: weierophinney

docs/book/v3/features/template/twig.md

@@ -114,6 +114,7 @@ return [
         ],
     ],
     'twig' => [
+        'autoescape' => 'html', // Auto-escaping strategy [html|js|css|url|false]
         'cache_dir' => 'path to cached templates',
         'assets_url' => 'base URL for assets',
         'assets_version' => 'base version for assets',
@@ -124,6 +125,11 @@ return [
             // Global variables passed to twig templates
             'ga_tracking' => 'UA-XXXXX-X'
         ],
+				'optimizations' => -1, // -1: Enable all (default), 0: disable optimizations
+				'runtime_loaders' => [
+						// runtime loader names or instances
+				],
+				'timezone' => 'default timezone identifier, e.g. America/New_York',
     ],
 ];
 ```