Fix left navigation not showing

_data/nav.yml

@@ -0,0 +1,40 @@
+docs:
+
+  - title: Go database/sql tutorial
+    url: index.html
+
+  - title: Overview
+    url: overview.html
+
+  - title: Importing a Database Driver
+    url: importing.html
+
+  - title: Accessing the Database
+    url: accessing.html
+
+  - title: Retrieving Result Sets
+    url: retrieving.html
+
+  - title: Modifying Data and Using Transactions
+    url: modifying.html
+
+  - title: Using Prepared Statements
+    url: prepared.html
+
+  - title: Handling Errors
+    url: errors.html
+
+  - title: Working with NULLs
+    url: nulls.html
+
+  - title: Working with Unknown Columns
+    url: varcols.html
+
+  - title: The Connection Pool
+    url: connection-pool.html
+
+  - title: Surprises, Antipatterns and Limitations
+    url: surprises.html
+
+  - title: Related Reading and Resources
+    url: references.html

_includes/leftnav.html

@@ -1,23 +1,11 @@
 <div class="leftnav">
   <ul class="nav nav-list">
-{% for group in page.nav %}
-  {% capture group_url %}/{{ page.name }}/{{ group.url }}{% endcapture %}
-  <li class="nav-header{% if page.url == node_url %} active{% endif %}">
-    {% if page.url %}
-      <a href="{{group.url}}">{{group.name}}</a>
-    {% else %}
-      {{group.name}}
-    {% endif %}
-  </li>
-  {% for node in group.articles %}
-    {% capture node_url %}/{{ page.name }}/{{ node.url }}{% endcapture %}
-    {% if page.url == node_url %}
-      <li class="active"><a href="{{node.url}}">{{node.title}}</a></li>
-    {% else %}
-      <li><a href="{{node.url}}">{{node.title}}</a></li>
-    {% endif %}
-  {% endfor %}
-{% endfor %}
+    {% for doc in site.data.nav.docs %}
+      {% assign curr_url = page.url | remove_first: "/" %}
+      <li class="{% if doc.url == 'index.html' %}nav-header{% endif %} {% if curr_url == doc.url %}active{% endif %}">
+        <a href="{{ doc.url }}">{{ doc.title }}</a>
+      </li>
+    {% endfor %}
   </ul>
   <hr />
   <div class="license">