Add missing footers

In #1152 the footer partial was only added to the index.rhtml file.
This commit adds the footer partial to the other template files.

Author: st0012

lib/rdoc/generator/template/darkfish/class.rhtml

@@ -16,6 +16,8 @@
     <%= render '_sidebar_extends.rhtml' %>
     <%= render '_sidebar_methods.rhtml' %>
   </div>
+
+  <%= render '_footer.rhtml' %>
 </nav>
 
 <main role="main" aria-labelledby="<%=h klass.aref %>">

lib/rdoc/generator/template/darkfish/page.rhtml

@@ -12,6 +12,8 @@
   <div id="project-metadata">
     <%= render '_sidebar_pages.rhtml' %>
   </div>
+
+  <%= render '_footer.rhtml' %>
 </nav>
 
 <main role="main" aria-label="Page <%=h file.full_name%>">

lib/rdoc/generator/template/darkfish/servlet_not_found.rhtml

@@ -10,6 +10,8 @@
     <%= render '_sidebar_pages.rhtml' %>
     <%= render '_sidebar_classes.rhtml' %>
   </div>
+
+  <%= render '_footer.rhtml' %>
 </nav>
 
 <main role="main">

lib/rdoc/generator/template/darkfish/servlet_root.rhtml

@@ -12,7 +12,8 @@
     <%= render '_sidebar_search.rhtml' %>
   </div>
 
-<%= render '_sidebar_installed.rhtml' %>
+  <%= render '_sidebar_installed.rhtml' %>
+  <%= render '_footer.rhtml' %>
 </nav>
 
 <main role="main">

lib/rdoc/generator/template/darkfish/table_of_contents.rhtml

@@ -7,6 +7,8 @@
 
     <%= render '_sidebar_search.rhtml' %>
   </div>
+
+  <%= render '_footer.rhtml' %>
 </nav>
 <main role="main">
 <h1 class="class"><%= h @title %></h1>