make /documentation/ redirect to /documentation/getting-started/

this path has not been used, maybe it should but redirecting now to
where the current main documentation is

Author: jasalt

content/documentation/_index.md

@@ -4,4 +4,16 @@ insert_anchor_links = "right"
 paginate_by = 5
 +++
 
-Documentation
+# Documentation
+
+Welcome to the Phel documentation. Here you'll find comprehensive guides and references for using Phel.
+
+<div class="redirect-notice">
+    <p><strong>Notice:</strong> You will be automatically redirected to the <a href="/documentation/getting-started/">Getting Started</a> guide in a few seconds.</p>
+</div>
+
+<script>
+    setTimeout(function() {
+        window.location.href = "/documentation/getting-started/";
+    }, 3000);
+</script>