I would say they're of equal importance, and regardless, you're misunderstanding its effect on the document outline anyway, even with your change it stills reads as:

- Radminton Badminton Club
- About the club
- Venue
  - Address:
- Membership
- League
- Get in touch
- Club photos

Install the `HTML5 outline` extension for Chrome if you don't already have it (or something better).