fix(format-transformer): set overflow for output area width (CorentinTh#787)

Author: code2933

src/components/FormatTransformer.vue

@@ -48,7 +48,7 @@ const output = computed(() => transformer.value(input.value));
     monospace
   />
 
-  <div>
+  <div overflow-auto>
     <div mb-5px>
       {{ outputLabel }}
     </div>