Doc: Add `toc' view script

refs #4820

modules/doc/application/views/scripts/partials/toc.phtml

@@ -0,0 +1,14 @@
+<div class="controls">
+  <h1><?= $docName ?> documentation</h1>
+</div>
+<div class="content" data-base-target="_next">
+<?= $this->partial(
+  'layout/menu.phtml',
+  'default',
+  array(
+    'items' => $docToc->getChildren(),
+    'sub'   => false,
+    'url'   => ''
+  )
+) ?>
+</div>