title: SectionList & Typescript
body: <p>What is the proper way to type SectionList? I'm running into a bug where this works (from the <a href="https://facebook.github.io/react-native/docs/sectionlist" rel="nofollow noreferrer">docs example</a>):</p>
  
  <pre><code>        &lt;SectionList
            renderItem={({item, index}) =&gt; &lt;Text key={index}&gt;{item}&lt;/Text&gt;}
            renderSectionHeader={({section: {title}}) =&gt; (
              &lt;Text style={{fontWeight: 'bold'}}&gt;{title}&lt;/Text&gt;
            )}
            sections={ticksData}
            keyExtractor={(item, index) =&gt; item + index}
          /&gt;;
  </code></pre>
  
  <p>But this doesn't:</p>
  
  <pre><code>const renderSectionHeader=({section: {title}}) =&gt; (
    &lt;Text style={{fontWeight: 'bold'}}&gt;{title}&lt;/Text&gt;
   );
  
  return (
          &lt;SectionList
            renderItem={({item, index}) =&gt; &lt;Text key={index}&gt;{item}&lt;/Text&gt;}
            renderSectionHeader={renderSectionHeader}
            sections={ticksData}
            keyExtractor={(item, index) =&gt; item + index}
          /&gt;;
  </code></pre>
  
  <p>I get this error:</p>
  
  <blockquote>
    <p>Types of property 'renderSectionHeader' are incompatible. Type '({ section: { title } }: { section: { title: any; }; }) => Element' is not assignable to type '(info: { section: SectionListData; }) => ReactElement'. Types of parameters '__0' and 'info' are incompatible. Type '{ section: SectionListData; }' is not assignable to type '{ section: { title: any; }; }'. Types of property 'section' are incompatible. Type 'SectionListData' is not assignable to type '{ title: any; }'. Property 'title' is missing in type 'SectionListData'.</p>
  </blockquote>