React JS Tutorial - #14 Error Handling

Following up on the previous video where we validated the form before passing its input to the countdown, we'd now want to provide visual feedback to the user as to whether the input was deemed valid or not. With Bulma, we can easily toggle helper classes to change the styling of our datepicker, as well as render additional text messages. Lastly, let's also refactor the form, such that the user input will be instantaneously validated and reflected in the UI on each keystroke.