chore: fixup

Author: nperez0111

examples/08-extensions/01-tiptap-arrow-conversion/src/ArrowConversionExtension.ts

@@ -13,7 +13,6 @@ export const ArrowConversionExtension = Extension.create({
           const tr = state.tr.replaceWith(from, to, state.schema.text("→"));
           chain().insertContent(tr).run();
         },
-        undoable: true,
       },
     ];
   },