draft new navigation buttons

src/Button/Back.php

@@ -0,0 +1,18 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Yggverse\Yoda\Button;
+
+class Back
+{
+    public \GtkButton $button;
+
+    public function __construct(
+        ?string $label = 'Back'
+    ) {
+        $this->button = \GtkButton::new_with_label(
+            $label
+        );
+    }
+}