feat(CSS): add styles for new hi-classes

scenarios/xslt/edxml2html/css/styles.css

@@ -232,6 +232,20 @@ hr.metamark-line.doubleLine {
 
 }
 
+/*----------------------------------{ HIGHLIGHTINGS }--------------------------------*/
+
+.bold {
+   font-weight: bold;
+}
+
+.italics {
+    font-style: italic;
+}
+
+.under {
+    text-decoration: underline;
+}
+
 /*----------------------------------{ ITEMS }--------------------------------*/
 .item {
     vertical-align: top;