Adding Table Of Contents to pages for easier navigation

Change-Id: I50f536407c57bbc908d32ceb1884f0f25340ec54
diff --git a/book.json b/book.json
index bdd49dd..93474f0 100644
--- a/book.json
+++ b/book.json
@@ -9,6 +9,7 @@
   },
   "plugins": [
     "anchorjs",
-    "smart-nav-collapse"
+    "smart-nav-collapse",
+    "page-toc"
   ]
 }