[TASK] Docs update to help users with CoreDNS rewrites related to identity and web modeler

[jessesimpson36]

Related to

SUPPORT-21543 SUPPORT-22007

As part of the above issue, when setting up an environment running on your local machine, often, people will use DNS or /etc/resolv.conf entries for localhost, which resolves to whatever pod makes the request. There are 2 scenarios where this can be problematic:

1. When deploying a model, and using the external-facing URL for the zeebe gateway, if the web modeler requests to zeebe.dev.local.ultrawombat.com, then it will evaluate to the web modeler pod 127.0.0.1 rather than the zeebe gateway ip.
2. When identity is requesting a refresh token, it will use the external-facing url for the keycloak URL because the url in the JWT must match the request URL (as of keycloak 23). If this evaluates to 127.0.0.1, then the request will route to the identity pod.

I'm thinking we could include a documentation update which will inform users how to do this DNS rewrite query.

example:

        rewrite name substring zeebe.local.distro.ultrawombat.com ingress-nginx-controller.ingress-nginx.svc.cluster.local
        rewrite name substring keycloak.local.distro.ultrawombat.com ingress-nginx-controller.ingress-nginx.svc.cluster.local

OR

We could inform customers in the documentation to get them to stop using 127.0.0.1, and instead use their 192.168.1.x local address.