Categorise specifications

i2p2www/pages/spec/index.html

@@ -27,6 +27,7 @@ If you find any inaccuracies in the documents linked below, please
 <table>
   <tr>
     <th>Title</th>
+    <th>Category</th>
     <th>Last updated</th>
     <th>Accurate for</th>
     <th>Link</th>
@@ -34,6 +35,7 @@ If you find any inaccuracies in the documents linked below, please
   {% for spec in specs %}
   <tr>
     <td>{{ spec.title }}</td>
+    <td>{{ spec.category }}</td>
     <td><time>{{ spec.lastupdated }}</time></td>
     <td>{{ spec.accuratefor }}</td>
     <td>