Fix sidebars CSS naming

Author: liborjelinek

src/ablog/templates/ablog/archives.html

@@ -1,5 +1,5 @@
 {% if ablog.archive %}
-<div class="ablog-sidebar-item ablog__archive">
+<div class="ablog-sidebar-item ablog__archives">
   <h3>
     <a href="{{ pathto(ablog.archive.docname) }}">{{ gettext('Archives') }}</a>
   </h3>

src/ablog/templates/ablog/categories.html

@@ -1,5 +1,5 @@
 {% if ablog.category %}
-<div class="ablog-sidebar-item ablog__category">
+<div class="ablog-sidebar-item ablog__categories">
   <h3>
     <a href="{{ pathto(ablog.category.path) }}">{{ gettext('Categories') }}</a>
   </h3>

src/ablog/templates/ablog/tagcloud.html

@@ -1,5 +1,5 @@
 {% if ablog.tags %}
-<div class="ablog-sidebar-item ablog__tags">
+<div class="ablog-sidebar-item ablog__tagcloud">
   <link
     rel="stylesheet"
     href="{{ pathto('_static/ablog/tagcloud.css', 1) }}"