update README.

Author: xgfd3

README.md

@@ -10,8 +10,8 @@ This repository contains sample projects for the Agora RTC Native SDK, including
 | -------- | -------- | ------------------------------------------------------ | ------------------------------------------------------------ |
 | Android  | Java     | [/Android/APIExample](/Android/APIExample)             | [RTC Java Video SDK](https://docs.agora.io/en/video-call-4.x-beta/API%20Reference/java_ng/API/rtc_api_overview_ng.html) |
 | Android  | Java     | [/Android/APIExample-Audio](/Android/APIExample-Audio) | [RTC Java Audio SDK](https://docs.agora.io/en/voice-call-4.x-beta/API%20Reference/java_ng/API/rtc_api_overview_ng.html) |
-| iOS      | Swift    | [/iOS/APIExample](/iOS/APIExampe)                      | [RTC Objective-C Video SDK](https://docs.agora.io/en/video-call-4.x-beta/API%20Reference/ios_ng/API/rtc_api_overview_ng.html) |
-| iOS      | Swift    | [/iOS/APIExample-Audio](/iOS/APIExampe-Audio)          | [RTC Objective-C Audio SDK](https://docs.agora.io/en/voice-call-4.x-beta/API%20Reference/ios_ng/API/rtc_api_overview_ng.html) |
+| iOS      | Swift    | [/iOS/APIExample](/iOS/APIExample)                     | [RTC Objective-C Video SDK](https://docs.agora.io/en/video-call-4.x-beta/API%20Reference/ios_ng/API/rtc_api_overview_ng.html) |
+| iOS      | Swift    | [/iOS/APIExample-Audio](/iOS/APIExample-Audio)         | [RTC Objective-C Audio SDK](https://docs.agora.io/en/voice-call-4.x-beta/API%20Reference/ios_ng/API/rtc_api_overview_ng.html) |
 | macOS    | Swift    | [/macOS](/macOS)                                       | [RTC Objective-C Video SDK](https://docs.agora.io/en/video-call-4.x-beta/API%20Reference/mac_ng/API/rtc_api_overview_ng.html) |
 | Windows  | C++      | [/windows](/windows)                                   | [RTC C++ Video SDK](https://docs.agora.io/en/video-call-4.x-beta/API%20Reference/windows_ng/API/rtc_api_overview_ng.html) |