Undocumented breaking change for operator cluster-wide resource watching

[rkthtrifork]

The following commit changes the operator from watching all namespaces to only watching its own namespace which is a pretty big breaking change https://github.com/cloudnative-pg/charts/blame/dc3137ebbcf019515281da40dbfa10b635ebfd87/charts/cloudnative-pg/templates/deployment.yaml#L86

The only documentation i see for the change is tucked away in a release for the cluster chart https://github.com/cloudnative-pg/charts/releases/tag/cluster-v0.1.1

It should probably be documented in the newest release for the operator and maybe even put under a "Breaking Changes" section in the release or the default should be that the operator watches cluster-wide