Add config rule for db-instance-backup-enabled

[ccggeo]

Hey

Added to the module to add the db-instance-backup-enabled rule. Lemme know if I need to add some testing and I will rectify.

Many thanks,

[esacteksab]

Hi @ccggeo, Apologies for the lack of a response. A test would be prefect. Also, looks like there may be a conflict now. Thank you for your time and your contribution. Much appreciated!

Barry

[rpdelaney]

Closing this as stale for now.