Make navigation menus reusable

site/_includes/docs_option.html

@@ -0,0 +1,11 @@
+{% assign items = include.items | split: ' ' %}
+
+{% for item in items %}
+  {% assign item_url = item | prepend:'/docs/' | append:'/' %}
+
+  {% for p in site.pages %}
+    {% if p.url == item_url %}
+      <option value="{{ site.url }}{{ p.url }}">{{ p.title }}</option>
+    {% endif %}
+  {% endfor %}
+{% endfor %}

site/_includes/docs_ul.html

@@ -0,0 +1,20 @@
+{% assign items = include.items | split: ' ' %}
+
+<ul>
+{% for item in items %}
+  {% assign item_url = item | prepend:'/docs/' | append:'/' %}
+
+  {% if item_url == page.url %}
+    {% assign c = 'current' %}
+  {% else %}
+    {% assign c = '' %}
+  {% endif %}
+
+  {% for p in site.pages %}
+    {% if p.url == item_url %}
+      <li class="{{ c }}"><a href="{{ p.url }}">{{ p.title }}</a></li>
+    {% endif %}
+  {% endfor %}
+
+{% endfor %}  
+</ul>