fixed a minor typo (#435)

that can still cause a lot of confusion :)

Author: mdugue

docs/react-testing-library/setup.md

@@ -214,7 +214,7 @@ _Typescript config needs to be updated as follow:_
  // ...,
 + "baseUrl": "src",
 + "paths": {
-+ "test-utils": ["../utils/test-utils"]
++ "test-utils": ["./utils/test-utils"]
 + }
  }
 }