chore(docs): update TOC

Author: julienloizelet

docs/USER_GUIDE.md

@@ -13,12 +13,15 @@
 - [Features](#features)
 - [Usage](#usage)
 - [Standalone bouncer set up](#standalone-bouncer-set-up)
+  - [Copy sources](#copy-sources)
   - [Files permission](#files-permission)
+  - [Composer](#composer)
   - [Settings file](#settings-file)
   - [`auto_prepend_file` directive](#auto_prepend_file-directive)
     - [`.ini` file](#ini-file)
     - [Nginx](#nginx)
     - [Apache](#apache)
+  - [Stream mode cron task](#stream-mode-cron-task)
 - [Create your own bouncer](#create-your-own-bouncer)
   - [Implementation](#implementation)
   - [Test your bouncer](#test-your-bouncer)