message: Fix typo on string
diff: @@ -67,7 +67,7 @@ A "Living Standard" ([example](https://xhr.spec.whatwg.org/)) should be added he
  ## Code Structure
  - `src/index.ts`: handles the emitting of the `.d.ts` files.
  -- `src/test.ts`: verifies the otuput by comparing the `generated/` and `baseline/` contents.
  +- `src/test.ts`: verifies the output by comparing the `generated/` and `baseline/` contents.
  ## Input Files
  