Fixed url in samples/readme.md

Removed leading "./" that was making it a relative url

samples/README.md

@@ -2,4 +2,4 @@
 
 | name | description |
 | :-------------: | :-------------: |
-| [agora-rn-quickstart](./https://github.com/agoraio-community/agora-rn-quickstart) | react-native-agora demo for beginner |
+| [agora-rn-quickstart](https://github.com/agoraio-community/agora-rn-quickstart) | react-native-agora demo for beginner |