Generate several sealed certs from multiple certificates

Which component: kubeseal (CLI)

Is your feature request related to a problem? Please describe. We run 2 clusters dev , prod with same applications but different kubeseal keys. I want to generate kubeseal secrets with same data for all clusters, in a single CLI command (as a good lazy developer...).

Describe the solution you'd like

CLI option --cert should accept an array.

CLI output should be a JSON array containing the sealed secrets as usually.

Describe alternatives you've considered Create a small shell wrapper

Additional context

Relates to https://github.com/bitnami-labs/sealed-secrets/issues/263