Set link colours to mustard initially and purple for visited

Author: thomasspriggs

src/cbmc_style.css

@@ -24,3 +24,12 @@ h3 {
 	font-size: 1.1em;
 	margin: 0.3em 0;
 }
+
+
+a {
+	color: #CA7900;
+}
+
+.contents a:visited {
+	color: #6237a8;
+}