Add missing user-event import

Author: nickserv

src/fixtures/example.test.js

@@ -3,6 +3,7 @@
  * @jest-environment-options { "url": "https://example.com/" }
  */
 const { screen, waitFor } = require("@testing-library/dom")
+const userEvent = require("@testing-library/user-event")
 require("@testing-library/jest-dom")
 
 test("Example", async () => {

src/index.ts

@@ -27,6 +27,7 @@ export class Extension implements StringifyExtension {
     out.appendLine(
       'const { screen, waitFor } = require("@testing-library/dom")',
     )
+    out.appendLine('const userEvent = require("@testing-library/user-event")')
     out.appendLine('require("@testing-library/jest-dom")')
 
     out.appendLine("")