Update readme, add support to undefined callbacks

example/src/App.tsx

@@ -1,7 +1,7 @@
 import * as React from 'react';
 
 import { Alert, StyleSheet, Text, View } from 'react-native';
-import { BigbluebuttonMobile } from 'bigbluebutton-mobile-sdk';
+import { BigBlueButtonMobile } from 'bigbluebutton-mobile-sdk';
 import type { INativeEvent } from './types';
 
 export default function App() {
@@ -32,7 +32,7 @@ export default function App() {
   return (
     <View style={styles.container}>
       {loadComponent ? (
-        <BigbluebuttonMobile
+        <BigBlueButtonMobile
           url="https://mobile.bbb.imdt.dev"
           style={styles.bbb}
           onError={(content: any) => handleOnError(content)}