update readme

README.md

 
 `npm install react-native-autoheight-webview@0.2.3 --save` (rn < 0.44)
 
-## android
+## Android
 `react-native link react-native-autoheight-webview`
+
 `import AutoHeightWebView from 'react-native-autoheight-webview';`
 
-## ios
+## iOS
 `import AutoHeightWebView from 'react-native-autoheight-webview';`
 
 ## showcase
-![react-native-autoheight-webview ios](https://media.giphy.com/media/g01cDWsKSzqLDAK8na/giphy.gif)&nbsp;
-![react-native-autoheight-webview android](https://media.giphy.com/media/35Dmikv0e0P5zVjTUw/giphy.gif)
+![react-native-autoheight-webview iOS](https://media.giphy.com/media/eehXhFjneVqEUCzYip/giphy.gif)&nbsp;
+![react-native-autoheight-webview Android](https://media.giphy.com/media/1yTcqipIfHbgNNfcEU/giphy.gif)
 
 ## usage
 
     // if page contains iframe on iOS, use a specific script for it
     hasIframe={true}
     /*
-    if set to false may cause some layout issues (width of container not fit for screen) on android
+    if set to false may cause some layout issues (width of container not fit for screen) on Android
     if set to true may cause some layout issues (smaller font size) on iOS
     */
-    scalesPageToFit={Platform.OS === 'android' ? true : false}
-    // baseUrl not work in android 4.3 or below version
+    scalesPageToFit={Platform.OS === 'Android' ? true : false}
+    // baseUrl not work in Android 4.3 or below version
     enableBaseUrl={true}
     // offset of rn webview margin 
     heightOffset={5}
     enableAnimation={true},
     // only works on enable animation
     animationDuration={255},
-    // only on android for animating size
+    // only on Android for animating size
     animationEasing={Easing.ease()},
     // or uri
     source={{ html: `<p style="font-weight: 400;font-style: normal;font-size: 21px;line-height: 1.58;letter-spacing: -.003em;">Tags are great for describing the essence of your story in a single word or phrase, but stories are rarely about a single thing. <span style="background-color: transparent !important;background-image: linear-gradient(to bottom, rgba(146, 249, 190, 1), rgba(146, 249, 190, 1));">If I pen a story about moving across the country to start a new job in a car with my husband, two cats, a dog, and a tarantula, I wouldn’t only tag the piece with “moving”. I’d also use the tags “pets”, “marriage”, “career change”, and “travel tips”.</span></p>` }}
-    // use local or remote files
+    /* 
+    use local or remote files
+    local files only works on enable baseUrl on Android,
+    to add local file on Android: rnproject/android/app/src/main/assets/web/,
+    to add local file on iOS: open iOS project with Xcode, 
+    add new group named web (with folder) under your project folder, then drag your files into this folder
+    */
     files={[{
         href: 'cssfileaddress',
         type: 'text/css',