Update README.md, consistent use of spaces instead of tabs, better examples

bin/triggering_congestion.php

@@ -0,0 +1,24 @@
+<?php
+
+use React\EventLoop\Factory;
+use Toalett\Multiprocessing\Concurrency;
+use Toalett\Multiprocessing\ContextBuilder;
+
+require_once __DIR__ . '/../vendor/autoload.php';
+
+$loop = Factory::create();
+$context = ContextBuilder::create()
+    ->withEventLoop($loop)
+    ->withConcurrency(Concurrency::atMost(4))
+    ->build();
+
+$context->on('booted', fn() => print("🚽 Toalett Multiprocessing Context\n"));
+$context->on('congestion', fn() => print('C'));
+$context->on('congestion_relieved', fn() => print('R'));
+$context->on('worker_started', fn() => print('+'));
+$context->on('worker_stopped', fn() => print('-'));
+
+$loop->addPeriodicTimer(1, fn() => $context->submit(fn(int $s) => sleep($s), random_int(0, 10)));
+
+print("Press CTRL+C to stop.\n");
+$context->run();