Created simple blog.

post.php

@@ -0,0 +1,18 @@
+<?php
+include 'includes/header.php';
+require_once 'Parsedown.php';
+
+$slug = $_GET['slug'] ?? '';
+$filepath = "posts/$slug.md";
+
+if (!preg_match('/^[a-zA-Z0-9\-]+$/', $slug) || !file_exists($filepath)) {
+    echo "<p>Beitrag nicht gefunden.</p>";
+    include 'includes/footer.php';
+    exit;
+}
+
+$md = file_get_contents($filepath);
+$Parsedown = new Parsedown();
+echo $Parsedown->text($md);
+
+include 'includes/footer.php';