Add index.md for GItHub pages (very temporary soln)

Author: trampgeek

index.md

@@ -0,0 +1,13 @@
+ ---
+  title: CodeRunner Documentation
+  ---
+
+  # CodeRunner Documentation
+
+  **→ [View Full Documentation](README.md)**
+
+  <script>
+  if (window.location.pathname.endsWith('/')) {
+    window.location.href = window.location.href + 'README.md';
+  }
+  </script>