add styles to support big and small roles

Author: nintendoeats

src/css/doc.css

@@ -222,6 +222,14 @@
   width: 100%;
 }
 
+.doc .big {
+  font-size: larger;
+}
+
+.doc .small {
+  font-size: smaller;
+}
+
 .doc .underline {
   text-decoration: underline;
 }