Fix documentation template

docs/theme/nav.html

 {%- if nav_item.url %}
-    <a class="{% if nav_item.active%}current{%endif%}" href="{{ nav_item.url }}">{{ nav_item.title }}</a>
+<a class="{% if nav_item.active%}current{%endif%}" href="{{ base_url }}/{{ nav_item.url }}">{{ nav_item.title }}</a>
 {%- else %}
-    <span class="caption-text">{{ nav_item.title }}</span>
+<span class="caption-text">{{ nav_item.title }}</span>
 {%- endif %}
 
 {%- if nav_item == page or nav_item.children %}
-    <ul class="subnav">
-        {%- if nav_item == page %}
-            {% include 'toc.html' %}
-        {%- endif %}
-        {%- if nav_item.children %}
-            {%- set navlevel = navlevel + 1%}
-            {%- for nav_item in nav_item.children %}
-                <li class="{% if navlevel > 2 %}toctree-l{{ navlevel }}{% endif %}{% if nav_item.active%} current{%endif%}">
-                    {% include 'nav.html' %}
-                </li>
-            {%- endfor %}
-            {%- set navlevel = navlevel - 1%}
-        {%- endif %}
-    </ul>
+<ul class="subnav">
+    {%- if nav_item == page %}
+    {% include 'toc.html' %}
+    {%- endif %}
+    {%- if nav_item.children %}
+    {%- set navlevel = navlevel + 1%}
+    {%- for nav_item in nav_item.children %}
+    <li class="{% if navlevel > 2 %}toctree-l{{ navlevel }}{% endif %}{% if nav_item.active%} current{%endif%}">
+        {% include 'nav.html' %}
+    </li>
+    {%- endfor %}
+    {%- set navlevel = navlevel - 1%}
+    {%- endif %}
+</ul>
 {%- endif %}

docs/theme/toc.html

 {% for toc_item in page.toc %}
-    <!--<li class="toctree-l{{ navlevel + 1 }}"><a href="{{ toc_item.url }}">{{ toc_item.title }}</a></li>-->
-    {% if toc_item.children %}
-        <ul>
-        {% for toc_item in toc_item.children %}
-            <li><a class="toctree-l{{ navlevel + 2 }}" href="{{ toc_item.url }}">{{ toc_item.title }}</a></li>
-        {% endfor %}
-        </ul>
-    {% endif %}
+<!--<li class="toctree-l{{ navlevel + 1 }}"><a href="{{ toc_item.url }}">{{ toc_item.title }}</a></li>-->
+{% if toc_item.children %}
+<ul>
+    {% for toc_item in toc_item.children %}
+    <li><a class="toctree-l{{ navlevel + 2 }}" href="{{ toc_item.url }}">{{ toc_item.title }}</a></li>
+    {% endfor %}
+</ul>
+{% endif %}
 {% endfor %}