[Website]: Change the "configure Kibana" hyperlink to point at the exact configuration step

### Type of issue

Other

### What documentation page is affected

https://www.elastic.co/docs/deploy-manage/deploy/self-managed/air-gapped-install

### What happened?

Hello Team,

In the document URL link attached for this request, there is a section [Elastic Package Registry](https://www.elastic.co/docs/deploy-manage/deploy/self-managed/air-gapped-install#air-gapped-elastic-package-registry) which has a `NOTE` as below:

> Besides setting up the EPR service, you also need to [configure Kibana](https://www.elastic.co/docs/deploy-manage/deploy/self-managed/air-gapped-install#air-gapped-kibana) to use this service. If using TLS with the EPR service, it is also necessary to set up Kibana to trust the certificate presented by the EPR.

The hyperlink for `configure Kibana` redirects to the generic section for configuration of Kibana, where as I feel it should be specific to the section where we advise on the property that should be defined for the air-gap EPR instance in the Kibana configuration file.

I would like to propose below changes with exact hyperlinks for EPR configuration and TLS certs in Kibana configuration file.

> Besides setting up the EPR service, you also need to [configure Kibana](https://www.elastic.co/docs/reference/fleet/air-gapped#air-gapped-diy-epr-kibana) to use this service. If you are using TLS with the EPR service, it is also necessary to set up Kibana to trust the [custom CA certificate](https://www.elastic.co/docs/reference/fleet/air-gapped#_using_custom_ca_certificates) presented by the EPR.

Feel free to disagree and close this request, if you feel this change doesn't align with the original intent of this `NOTE`.

Thank you.

### Additional info

_No response_