Add style to display notes on a different background than the main text


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@20097 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/docs/llvm.css b/docs/llvm.css
index 5a5a38f..a1dfa9e 100644
--- a/docs/llvm.css
+++ b/docs/llvm.css
@@ -66,6 +66,7 @@
                   padding: 0 1em 0 1em;
                   display:table;
                 }
+.doc_notes      { background: #fafafa; border: 1px solid #cecece; padding: 1em }
 
 TABLE.layout    { text-align: left; border: none; border-collapse: collapse;
                   padding: 4px 4px 4px 4px; }