Here you will find a link to all release notes for each version release of cert-manager:
v1.7
v1.6
v1.5
v1.4
v1.3
v1.2
v1.1
v1.0
v0.16
v0.15
v0.14
v0.13
v0.12
v0.11
v0.10
v0.9
v0.8
v0.7
v0.6
v0.5
v0.4
v0.3
v0.2
v0.1