extend limitations on accessible user names in case of custom OpenID Connect provider

[megglos]

Description

See https://camunda.slack.com/archives/C55U06YRG/p1737640933298559?thread_ts=1737636040.852219&cid=C55U06YRG

Effectively Optimize can't display accessible user names in case of a non Keycloak OIDC setup.

I thus extended the existing docs on limitations of this setup. I think that these are generally not easy to find 😅, I don't have a good improvement suggestion on that yet though.

When should this change go live?

• This is a bug fix, security concern, or something that needs urgent release support. (add bug or support label)
• This is already available but undocumented and should be released within a week. (add available & undocumented label)
• This is on a specific schedule and the assignee will coordinate a release with the DevEx team. (create draft PR and/or add hold label)
• This is part of a scheduled alpha or minor. (add alpha or minor label)
• There is no urgency with this change (add low prio label)

PR Checklist

• My changes are for the next minor and are in /docs directory (aka /next/).
• My changes are for an already released minor and are in /versioned_docs directory.

• I added a DRI, team, or delegate as a reviewer for technical accuracy and grammar/style:
  • Engineering team review
  • Technical writer review via @camunda/tech-writers unless working with an embedded writer.

[akeller]

I thus extended the existing docs on limitations of this setup. I think that these are generally not easy to find 😅, I don't have a good improvement suggestion on that yet though.

@conceptualshark is this something already on your radar?

[conceptualshark]

Left a small comment for formatting, but agree that this might not be the ideal place for limitations, assuming that's what's meant by them not being easy to find. I think they can live here for now/to get this information out, and I can make a follow-up issue to make some additional adjustments to this page.

[conceptualshark]

Suggested change

| Optimize | **Microsoft Entra ID:** <br/> `https://<OPTIMIZE_URL>/api/authentication/callback` <br/><br/> **Helm:** <br/> `https://<OPTIMIZE_URL>` | There is a fallback if you use the existing ENV vars to configure your authentication provider, if you use a custom `yaml`, you need to update your properties to match the new values in this guide.<br/><br/>When using an OIDC provider, the following features are not currently available: User permissions tab in collections, digests, `Alerts` tab in collections, accessible user names for Owners of resources - instead the `sub` claim value is displayed . |

| Optimize | **Microsoft Entra ID:** <br/> `https://<OPTIMIZE_URL>/api/authentication/callback` <br/><br/> **Helm:** <br/> `https://<OPTIMIZE_URL>` | There is a fallback if you use the existing ENV vars to configure your authentication provider, if you use a custom `yaml`, you need to update your properties to match the new values in this guide.<br/><br/>When using an OIDC provider, the following Optimize features are not currently available: <br/>- The user permissions tab in collections<br/>- The `Alerts` tab in collections<br/>- Digests<br/>- Accessible user names for Owners of resources (the `sub` claim value is displayed instead). |

With the diff for tables being what it is, I apologize if the suggestion unclear - is it possible to format this in a list to make it easier to read?

Also just confirming Alerts should be in backticks.