[Website]: Suggestion — Some users may need further clarification and links to the EPR for air-gapped installations.

### Type of issue

Missing information

### What documentation page is affected

https://www.elastic.co/docs/deploy-manage/deploy/cloud-on-k8s/air-gapped-install

### What happened?

Support sometimes receives questions requesting additional clarification and the location of EPR (Elastic Package Registry). While the associated document contains the information within the 'EXAMPLE' text and provides the statement *"The ECK operator can be run in an air-gapped environment without access to the open internet when configured to avoid pulling container images from docker.elastic.co."*
It does not provide any actual link to the official docker EPR. https://www.docker.elastic.co/

Additionally—some users may not be aware of how to create their own EPR, as described here https://www.elastic.co/docs/deploy-manage/deploy/self-managed/air-gapped-install#air-gapped-elastic-package-registry
Including a link to this section for cross-referencing may be helpful and avoid additional questions and eliminating ambiguity.

### Additional info

We generally see these questions from US-FED customers who are not fully familiar with Docker/Kubernetes.

## Actions
_added by @georgewallace_
- Need to validate if the additions added in Feb have resolved this issue.
- Determine if other deployment type are impacted.