title: RNTMap was not found in the UIManager
body: <p>I am following along the official documentation, copy and pasting the code provided there:</p>
  
  <p><a href="https://facebook.github.io/react-native/docs/0.56/native-components-ios" rel="noreferrer">https://facebook.github.io/react-native/docs/0.56/native-components-ios</a></p>
  
  <p>But I am still running into this error <img src="https://i.stack.imgur.com/oop2d.png" alt="screenshot"></p>
  
  <p>does anyone know what the docs are missing to get this working?</p>