better preview

script.js

@@ -105,7 +105,7 @@ async function run() {
     textareaGameDataInput.addEventListener("change", checkGameData);
     textareaGameDataInput.addEventListener("keyup",  checkGameData);
     checkGameData();
-    
+
     imagePreview.style.display = "none";
 
     el('image').addEventListener('change', function () {
@@ -123,6 +123,7 @@ async function run() {
         }
     }
 
+    inputPrefix.addEventListener("keyup", handleTilePrefix);
     inputPrefix.addEventListener("change", handleTilePrefix);
     handleTilePrefix();