Improve documentation (v1.2.2)

[Tosta-Mista]

Hello,

I tried to follow your documentation, in order to install dsv-syncer and injector on a Kubernetes cluster (rke2). As we have our instance located in europe (tld = eu).

Unfortunately, in the documentation there's no example to change the TLD so I decided to add it in my PR.

I also got a patch error (on the syncer side) if I didn't add a dummy value in the secret data, so I also modified this part in the documentation.

Thank you for the work you do and I hope my PR is done properly.

Best regards,

[sheldonhull]

fixed by 5e21066