title: How would I grow <TextInput> height upon text wrapping?
body: <p>I'm trying to create a <code>&lt;TextInput&gt;</code> that can grow in height when the text wraps to the next line, similar to how Slack's message input grows with the text up to a point.</p>
  
  <p><img src="https://raw.githubusercontent.com/slackhq/SlackTextViewController/master/Screenshots/slacktextviewcontroller_demo.gif" alt="Slack input"></p>
  
  <p>I have the <code>multiline</code> prop set, so it is wrapping but the docs don't seem to mention any event regarding wrapping, and the only thing I can think of is a really hacky strategy to character count to figure out when to increase height of the input. How would I accomplish this?
  <a href="https://facebook.github.io/react-native/docs/textinput.html" rel="noreferrer">https://facebook.github.io/react-native/docs/textinput.html</a></p>