docs: add user guide

user_guide_src/source/incoming/routing.rst

@@ -76,6 +76,24 @@ You can supply multiple verbs that a route should match by passing them in as an
 .. literalinclude:: routing/004.php
    :lines: 2-
 
+Array Callable Syntax
+=====================
+
+Since v4.2.0, you can use array callable syntax to specify the controller:
+
+.. literalinclude:: routing/004_1.php
+   :lines: 2-
+
+Or using ``use`` keyword:
+
+.. literalinclude:: routing/004_2.php
+   :lines: 2-
+
+When you specify parameters:
+
+.. literalinclude:: routing/004_3.php
+   :lines: 2-
+
 Placeholders
 ============
 

user_guide_src/source/incoming/routing/004_1.php

@@ -0,0 +1,3 @@
+<?php
+
+$routes->get('/', [\App\Controllers\Home::class, 'index']);

user_guide_src/source/incoming/routing/004_2.php

@@ -0,0 +1,5 @@
+<?php
+
+use App\Controllers\Home;
+
+$routes->get('/', [Home::class, 'index']);

user_guide_src/source/incoming/routing/004_3.php

@@ -0,0 +1,5 @@
+<?php
+
+use App\Controllers\Product;
+
+$routes->add('product/(:num)/(:num)', [[Product::class, 'index'], '$1/$2']);