accordion .first-child selectors now less greedy

This allows wrapping divs around .title/.content
without loosing the top borders.

src/modules/accordion.less

@@ -55,8 +55,8 @@
     background-color 0.2s ease-out
   ;
 }
-.ui.accordion .title:first-child,
-.ui.accordion .accordion .title:first-child {
+.ui.accordion > .title:first-child,
+.ui.accordion .accordion > .title:first-child {
 	border-top: none;
 }
 
@@ -208,4 +208,4 @@
 .ui.fluid.accordion,
 .ui.fluid.accordion .accordion {
   width: 100%;
-}
+}