add css

src/client/styles/scss/_linkedit-preview.scss

@@ -4,7 +4,9 @@
     padding-top: 0px;
     margin: 0px -10px 0px -10px;
     .wiki {
+      width: 200%;
       overflow-y: scroll;
+      transform: scale(0.5) translate(-50%, -50%);
     }
   }
 }