playground: Make query error underlines render in safari

Author: maxbrunsfeld

cli/src/playground.html

@@ -166,6 +166,7 @@
 
     .query-error {
       text-decoration: underline red dashed;
+      -webkit-text-decoration: underline red dashed;
     }
   </style>
 </body>

docs/assets/css/style.scss

@@ -185,4 +185,5 @@ a.highlighted {
 
 .query-error {
   text-decoration: underline red dashed;
+  -webkit-text-decoration: underline red dashed;
 }