[Console] Improved the explanation of the hasOption() method

src/Symfony/Component/Console/Input/InputDefinition.php

@@ -282,6 +282,9 @@ class InputDefinition
     /**
      * Returns true if an InputOption object exists by name.
      *
+     * This method can't be used to check if the user included the option when
+     * executing the command (use getOption() instead).
+     *
      * @param string $name The InputOption name
      *
      * @return bool true if the InputOption object exists, false otherwise