Update blog layout

Author: knolleary

_layouts/blog.html

@@ -1,9 +1,11 @@
 {% include header.html %}
+{% assign top_url = '/blog' %}
+{% assign top_slug = 'blog' %}
 {% assign author = site.authors[page.author] %}
 <div class="docs">
+    {% include breadcrumbs.html %}
   <div class="grid docs-content">
     <div class="col-2-12 sidebar">
-      <a href="/blog">&larr; back</a>
     </div>
     <div class="col-8-12">
         <div class="post-header">