Add SIGINFO to documentation (#2762)
Add SIGINFO to documentation (#2762)

The feature was added in https://github.com/puma/puma/pull/1320 but was missing from documentation.
puma/puma,eileencodes/puma,puma/puma,puma/puma,eileencodes/puma,eileencodes/puma,eileencodes/puma,puma/puma