Fix typo in renderItem usage snippet (#35416)

Summary:
Fix typo in renderItem usage snippet - TouchableOpacity's JSX closing tag

## Changelog

[General] [Fixed] - Message

Pull Request resolved: https://github.com/facebook/react-native/pull/35416

Test Plan: N/A - Typo is in a comment

Reviewed By: christophpurrer

Differential Revision: D41445946

Pulled By: NickGerleman

fbshipit-source-id: 147226f9b0ef443908f71d25ccf8063b8c1c6142

Libraries/Lists/FlatList.d.ts

@@ -187,7 +187,7 @@ export interface FlatListProps<ItemT> extends VirtualizedListProps<ItemT> {
    * _renderItem = ({item}) => (
    *   <TouchableOpacity onPress={() => this._onPress(item)}>
    *     <Text>{item.title}</Text>
-   *   <TouchableOpacity/>
+   *   </TouchableOpacity>
    * );
    * ...
    * <FlatList data={[{title: 'Title Text', key: 'item1'}]} renderItem={this._renderItem} />