chore: 📝 Fix readme typo (#403)

Author: ujas-m-simformsolutions

README.md

@@ -354,15 +354,15 @@ playerController.release();
 ```
 #### Stopping players all at once
 ```dart
-playerController.stopAllPlayer();
+playerController.stopAllPlayers();
 ```
 There could be any number of players but you can just call this function from any **one** player and it will stop all the players.
 
 #### Pausing players all at once
 ```dart
 playerController.pauseAllPlayers();
 ```
-This function works similar to stopAllPlayer but just pauses all players.
+This function works similar to stopAllPlayers but just pauses all players.
 
 #### Disposing the controller
 ```dart