Renaming story filenames and changed 'tags' to 'topics'

_layouts/story.html

@@ -5,7 +5,7 @@ layout: default
 
   <header class="post-header">
     <h1 class="post-title">
-      {{ page.topic | escape}}<br>
+      {{ page.subject | escape}}<br>
       <small>{{ page.narrator | escape }}</small>
     </h1>
   </header>