added example from readme

Author: splitbrain

examples/minimal.php

@@ -0,0 +1,28 @@
+#!/usr/bin/php
+<?php
+require __DIR__ . '/../vendor/autoload.php';
+use splitbrain\phpcli\CLI;
+use splitbrain\phpcli\Options;
+
+class Minimal extends CLI
+{
+    // register options and arguments
+    protected function setup(Options $options)
+    {
+        $options->setHelp('A very minimal example that does nothing but print a version');
+        $options->registerOption('version', 'print version', 'v');
+    }
+
+    // implement your code
+    protected function main(Options $options)
+    {
+        if ($options->getOpt('version')) {
+            $this->info('1.0.0');
+        } else {
+            echo $options->help();
+        }
+    }
+}
+// execute it
+$cli = new Minimal();
+$cli->run();