On the site documentation section, links to documentation items point to the "jekyllrb.com" website, this means that users testing changes might get confused because they will see the official external website instead of their local website upon clicking those links.

site/_includes/docs_option.html

@@ -1,5 +1,5 @@
 {% for item in include.items %}
   {% assign item_url = item | prepend:"/docs/" | append:"/" %}
   {% assign doc = site.docs | where: "url", item_url | first %}
-  <option value="{{ site.url }}{{ doc.url }}">{{ doc.title }}</option>
+  <option value="{{ doc.url }}">{{ doc.title }}</option>
 {% endfor %}

site/_includes/docs_ul.html

@@ -2,6 +2,6 @@
 {% for item in include.items %}
   {% assign item_url = item | prepend:"/docs/" | append:"/" %}
   {% assign p = site.docs | where:"url", item_url | first %}
-  <li class="{% if item_url == page.url %}current{% endif %}"><a href="{{ site.url }}{{ p.url }}">{{ p.title }}</a></li>
+  <li class="{% if item_url == page.url %}current{% endif %}"><a href="{{ p.url }}">{{ p.title }}</a></li>
 {% endfor %}
 </ul>