ISTWCMS-4754: Add basic 'kbd' styling

css/uw_ckeditor.css

@@ -17,3 +17,16 @@
   line-height: 1.4;
   color: #757575;
 }
+
+kbd {
+  border: 1px solid #757575;
+  border-radius: 4px;
+  background: #dfdfdf;
+  margin: 0 1px;
+  padding: 0 4px;
+}
+
+kbd > kbd {
+  background: #575757;
+  color: #ffffff;
+}