Set link colours to mustard initially and purple for visited

Author: thomasspriggs

src/cbmc_style.css

@@ -28,3 +28,11 @@ h3 {
 p, div, ul, ol {
 	margin: 0.15em 0em 0.15em 0.5em;
 }
+
+a {
+	color: #CA7900;
+}
+
+.contents a:visited {
+	color: #6237a8;
+}