Fix Value model description

Author: slavvka

lib/internal/Magento/Framework/App/Config/Value.php

@@ -8,6 +8,10 @@
 /**
  * Config data model
  *
+ * This model is temporarily marked as API since {@see \Magento\Framework\App\Config\ValueInterface} doesn't fit
+ * developers' needs of extensibility. In 2.4 we are going to introduce a new iterface which should cover all needs
+ * and deprecate the mentioned together with the model
+ *
  * @method string getScope()
  * @method \Magento\Framework\App\Config\ValueInterface setScope(string $value)
  * @method int getScopeId()