release 3.13.1

release v3.13.0

release v3.12.0

release v3.11.0

release v3.10.0

release v3.9.0

CHANGELOG: prepare for v3.8.0

release v3.7.0

release v3.6.0

CHANGELOG: write entry for 3.5.1

Like github.com/burrowers/garble, we now include links too.