Converting nav to supporting category pages.

_includes/nav.html

@@ -4,6 +4,8 @@
   {%- if my_page.title -%}
     {%- if my_page.url == page.url -%}
       <li><a class="active" href="#top">{{ my_page.title }}</a></li>
+    {%- elsif page.url contains my_page.url and my_page.url != "/" -%}
+      <li><a class="active" href="{{ my_page.url | relative_url }}">{{ my_page.title }}</a></li>
     {%- else -%}
       <li><a href="{{ my_page.url | relative_url }}">{{ my_page.title }}</a></li>
     {%- endif -%}

_includes/posts.html

@@ -0,0 +1,35 @@
+{%- for category in site.categories -%}
+  {%- if category[0] != page.category -%}
+    {%- continue -%}
+  {%- endif -%}
+
+  {%- assign posts = category[1] -%}
+
+  {%- if posts.size > 0 -%}
+    <section id="articles" class="">
+      <div class="container">
+        {%- if page.list_title -%}
+          <h3>{{ page.list_title | capitalize }}</h3>
+        {%- endif -%}
+        <div class="features">
+          {%- assign date_format = site.date_format | default: "%b %-d, %Y" -%}
+          {%- for post in posts -%}
+            <article>
+              <a href="{{ post.url | relative_url }}" class="image">
+                <img src="{{ post.banner }}" alt="">
+              </a>
+              <div class="inner">
+                <h4><a href="{{ post.url | relative_url }}">{{ post.title | escape }}</a></h4>
+                {{ post.date | date: date_format }}
+                {%- if site.show_excerpts -%}
+                  {{ post.excerpt }}
+                {%- endif -%}
+              </div>
+            </article>
+          {%- endfor -%}
+        </div>
+      </div>
+    </section>
+  {%- endif -%}
+  {%- break -%}
+{%- endfor -%}

_layouts/category.html

@@ -0,0 +1,7 @@
+---
+layout: default
+---
+
+{{ content }}
+
+{% include posts.html %}