Documentation: Add list of supported resource_kind to sysdig_secure_posture_control

[brian-morrissey]

Documentation: Add list of supported resource_kind to sysdig_secure_posture_control
Location: /sysdiglabs/terraform-provider-sysdig/blob/master/website/docs/r/secure_posture_control.md

Current Wording:

[resource_kind] (Required) The Posture Control Resource kind. It should be a supported resource kind, eg. AWS_S3_BUCKET

Suggest adding a list of supported resource_kind to sysdig_secure_posture_control documentation. With the release of Kubernetes custom controls it appears Deployment, DaemonSet, CronJob and other resource_kinds were added but it is not easy for a user to identify.