fix image width in newsletter

Author: nasa42

themes/newsletter/templates/base.html

@@ -18,6 +18,10 @@
        border-top: 5px solid #000000;
      }
 
+     .container img {
+       max-width: 100%;
+     }
+
      table .row {
        border-collapse: collapse;
        width: 660px;