Update OPDS-part to display publishers

cps/templates/feed.xml

@@ -43,6 +43,9 @@
     <author>
       <name>{{entry.authors[0].name}}</name>
     </author>
+    <publisher>
+      <name>{{entry.publishers[0].name}}</name>
+    </publisher>
     <dcterms:language>{{entry.language}}</dcterms:language>
     {% for tag in entry.tags %}
     <category scheme="http://www.bisg.org/standards/bisac_subject/index.html"

cps/templates/index.xml

@@ -61,7 +61,14 @@
     <id>{{url_for('feed_authorindex')}}</id>
     <updated>{{ current_time }}</updated>
     <content type="text">{{_('Books ordered by Author')}}</content>
-    </entry>
+  </entry>
+  <entry>
+    <title>{{_('Publishers')}}</title>
+    <link rel="subsection" href="{{url_for('feed_publisherindex')}}" type="application/atom+xml;profile=opds-catalog"/>
+    <id>{{url_for('feed_publisherindex')}}</id>
+    <updated>{{ current_time }}</updated>
+    <content type="text">{{_('Books ordered by publisher')}}</content>
+  </entry>
   <entry>
     <title>{{_('Category list')}}</title>
     <link rel="subsection" href="{{url_for('feed_categoryindex')}}" type="application/atom+xml;profile=opds-catalog"/>