chore(docs/css): add margin between ul and p elements

Bootstrap CSS was removing the margin after ul elements if they were
descendents of other ul elements. But if the ul was followed by a p
then this looked terrible.

Related to angular#5953

Author: petebacondarwin

docs/app/assets/css/docs.css

@@ -211,6 +211,10 @@ code.highlighted {
   color:maroon;
 }
 
+ul + p {
+  margin-top: 10px;
+}
+
 .docs-version-jump {
   min-width:100%;
   max-width:100%;