feat: wordings corrected as suggested

Signed-off-by: yemkareems <yemkareems@gmail.com>

core/Command/User/ClearGeneratedAvatarCacheCommand.php

 	}
 
 	protected function execute(InputInterface $input, OutputInterface $output): int {
-		$output->writeln("clearing avatar cache started");
+		$output->writeln("Clearing avatar cache has started");
 		$this->avatarManager->clearCachedAvatars();
-		$output->writeln("cleared avatar cache successfully");
+		$output->writeln("Cleared avatar cache successfully");
 		return 0;
 	}
 }