Add example with nested submenu

Author: AydinHassan

examples/nested-submenu.php

@@ -0,0 +1,35 @@
+<?php
+
+use PhpSchool\CliMenu\CliMenu;
+use PhpSchool\CliMenu\CliMenuBuilder;
+
+require_once(__DIR__ . '/../vendor/autoload.php');
+
+$itemCallable = function (CliMenu $menu) {
+    echo $menu->getSelectedItem()->getText();
+};
+
+$menu = (new CliMenuBuilder)
+    ->setTitle('CLI Menu')
+    ->addItem('First Item', $itemCallable)
+    ->addItem('Second Item', $itemCallable)
+    ->addLineBreak('-')
+    ->addSubMenu('Options')
+        ->setTitle('CLI Menu > Options')
+        ->addItem('First option', function (CliMenu $menu) {
+            echo sprintf('Executing option: %s', $menu->getSelectedItem()->getText());
+        })
+        ->addSubMenu('Secret Options')
+            ->setTitle('CLI Menu > Options > Secret Options')
+            ->addItem('First secret option', function (CliMenu $menu) {
+                echo sprintf('Executing secret option: %s', $menu->getSelectedItem()->getText());
+            })
+            ->addLineBreak('-')
+            ->end()
+        ->addLineBreak('-')
+        ->end()
+    ->setWidth(70)
+    ->setBackgroundColour('yellow')
+    ->build();
+
+$menu->open();