Make Season Starts & Ends Required

In this video

We make the season start & end fields required.

Assignment: Group the Seasons together for Validation

1. Group the seasons controls together in the form in the component using a seasons formGroup.
2. Group them together in the HTML. Use the ng-container element.
3. Place the formGroup directive on the ng-container.
4. Don't forget to adjust the shape of the object in the pathValue call in editLeague.
5. Don't do any actual validation yet.