[tor-consensus-health] Discontinuing DocTor Notifications about Turtles

Hi, just a quick heads up that I'm discontinuing DocTor notifications about Turtles.

Turtles has been is an unhappy place for quite some time since Mike lacks the bandwidth to maintain it, and hasn't found someone to take it over. There's little point in continuing to issue notifications for it. Turtles constitutes the vast majority of DocTor's alerts, drowning out outher more correctable issues.

Cheers! -Damian