Add logging example

[irbekrm]

See this Slack conversation for context- it would be great if we could show users how to get log output with the example webhook (i.e replace fmt.Printf here with a log line

[mhkarimi1383]

@irbekrm
I think you can use github.com/cert-manager/cert-manager/pkg/logs but I used zap logger both of them are OK but if you want to have same log format I think you can use that

checkout https://github.com/ParminCloud/arvancloud-certmanager-issuer