Add usage examples.

examples/setting_error_handler.php

@@ -0,0 +1,43 @@
+<?php
+
+declare(strict_types=1);
+
+require_once __DIR__ . '/../vendor/autoload.php';
+
+use Phoundation\Bootstrap\Bootstrap;
+use Phoundation\Config\Loader\StaticConfigLoader;
+use Phoundation\Di\Container\Factory\ZendServiceManagerFactory;
+use Phoundation\ErrorHandling\Handler\LogHandler;
+use Phoundation\ErrorHandling\RunnerInterface;
+use Phoundation\ErrorHandling\WhoopsRunner;
+use Psr\Container\ContainerInterface;
+use Psr\Log\NullLogger;
+use Whoops\Run;
+
+$config = [
+    'db' => [
+        'dsn' => 'mysql:dbname=test;host=127.0.0.1',
+        'user' => 'root',
+        'password' => 'secret',
+    ],
+    'di' => [
+        'factories' => [
+            //automatically registered during bootstrap
+            RunnerInterface::class => function () {
+                $runner = new WhoopsRunner(new Run());
+                $runner->pushHandler(new LogHandler(new NullLogger()));
+
+                return $runner;
+            },
+        ]
+    ],
+];
+
+$bootstrap = new Bootstrap(
+    new StaticConfigLoader($config),
+    new ZendServiceManagerFactory()
+);
+/* @var $diContainer ContainerInterface */
+$diContainer = $bootstrap();
+
+assert($diContainer->has(RunnerInterface::class));