message: docs: correct spelling mistake in index.md
diff: @@ -220,7 +220,7 @@ You can use the `config:migrate` tool of `ts-jest` CLI if you're coming from an
  <div class="row"><div class="col-md-6" markdown="block">
  -_If you're using `jest.config.json`:_
  +_If you're using `jest.config.js`:_
  ```sh
  npx ts-jest config:migrate jest.config.js
  