title: How to add marker on react-native-maps. Documentation is not clear enough for beginners
body: <p>How can we add marker in a specific area if the code looks like something like this? Documentation is not enough clear for beginners. </p>
  
  <pre><code>&lt;View style={{marginTop:20, width:null, height:200}}&gt;  
     &lt;MapView
          style={{ flex: 1,width:null, height:200 }}
          initialRegion={{
            latitude: 37.78825,
            longitude: -122.4324,
            latitudeDelta: 0.0922,
            longitudeDelta: 0.0421,
          }}
        /&gt;   
        &lt;/View&gt;
  </code></pre>
  
  <p>How can it be included in this code?</p>