warned of beta

Shared with Chris B my double star portal page so to provide a handy reference to common double star discoverer codes and catalogue references. Warned it was by no means a complete list. Emphasised that the Struve clan was very active! I also gave a warning.

The other very confusing catalogue is Burnham. A lowercase Beta (β) is used with his doubles. This is NOT to be confused with the Bayer designation for stars.