[RELEASE] Operator v6.0.0

[djwfyi]

Operator v6.0.0 has changes that impact the docs:

Note that PR #2141 contains some documentation for v6.0.0.

• [x] Health info (color scheme) is added to info about tenants (PR #2116)
• [x] @djwfyi Secrets stay in the Operator namespace and no longer copy to the tenant (PR #2133)
• [x] @djwfyi Updated GitHub docs on TLS certificate flow with cert manager (PR #2079 and PR #2154) See also #1245.
• [x] @djwfyi Allow for seconds in K8s tolerations (PR #2168)
• [x] @feorlen Tokens verified directly with K8s instead of with MinIO (PR #2166)
• [x] @djwfyi Sidecar is its own container, reducing the need for rolling restarts (PR #2105)
• [x] @djwfyi Sidecar has been split out and now requires its own image info in the Helm chart (PR #2176)
• [x] @djwfyi Envvar moved to sidecar (this works in conjunction with #2176) (PR #2221)
• [ ] @feorlen Adds a tenant readiness endpoint (PR #2183)
• [ ] Deleting a tenant's storage now requires a manual task for k8s consistency (PR #2203)
• [x] @ravindk89 Removes the Operator GUI UI (PR #2205)
• [ ] Adds ability to expand a PVC (PR #2196)
• [x] @djwfyi Removes the field .spec.credsSecret in favor of .spec.configuration in tenant specs (PR #2217)

[djwfyi]

We do not discuss checking tenant health anywhere at the moment. Skipping 2116.

[djwfyi]

2168 is a bugfix; nothing to document.

[djwfyi]

2176 automatically covered with the Helm chart integration.

[feorlen]

Nothing required for https://github.com/minio/operator/pull/2166 console-sa, removed from current content along with other Operator Console instructions. Remaining references are all from deprecated instructions.

[ravindk89]

UI has been mostly removed, or possibly entirely removed. There may be trailing non-linked references that did not come up in grep though (or on orphaned pages, or related to the tenant console).