Update README.md

Author: famous90

README.md

@@ -90,7 +90,7 @@ $ npm run start
 
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-##Sound Effects
+## Sound Effects
 You can use different sound effects to enhance the user experience for events that take place while using Sendbird Calls. 
 
 To add sound effects, use the `SendBirdCall.addDirectCallSound(type: SoundType, uri: string)` method for the following events: dialing, ringing, reconnecting, and reconnected. Remember to set sound effects before the mentioned events occur. To remove sound effects, use the `SendBirdCall.Options.removeDirectCallSound(type: SoundType)` method.