feat: visualization of middleware flow

Signed-off-by: Arthur Schiwon <blizzz@arthur-schiwon.de>

developer_manual/basics/middlewares.rst

@@ -11,6 +11,9 @@ Middleware is logic that is run before and after each request and is modelled af
 * ``afterController``: This is being run after a successful controller method call and allows the manipulation of a Response object. The middleware is run in reverse order
 * ``beforeOutput``: This is being run after the response object has been rendered and allows the manipulation of the outputted text. The middleware is run in reverse order
 
+.. figure:: ../images/middleware-flow-horiz.png
+   :alt: Middleware flow chart
+
 To generate your own middleware, simply inherit from the Middleware class and overwrite the methods that should be used.
 
 
@@ -128,7 +131,7 @@ Middlewares can also be added using the **registerMiddleware** method of the con
 
       public function __construct(array $urlParams = []) {
           parent::__construct('myapp', $urlParams);
-  
+
           $container = $this->getContainer();
 
           // executed in the order that it is registered
@@ -142,7 +145,7 @@ Middlewares can also be added using the **registerMiddleware** method of the con
   The order is important! The middleware that is registered first gets run first in the **beforeController** method. For all other hooks, the order is being reversed, meaning: if a middleware is registered first, it gets run last.
 
 
-Parsing annotations 
+Parsing annotations
 -------------------
 
 Sometimes it is useful to conditionally execute code before or after a controller method. This can be done by defining custom annotations. An example would be to add a custom authentication method or simply add an additional header to the response. To access the parsed annotations, inject the **ControllerMethodReflector** class: