Replace interceptor link with hint to add full oauth url

[jonathanlukas]

The interceptor is not required in 8.2 anymore. Instead, here is a useful piece of information about the oauth url

closes #2237

Description

Until 8.2, it was required to use some kind of interceptor to achieve oauth behaviour on zeebe. As of 8.2, zeebe has an embedded oauth mode.

Now, it becomes more relevant to document the oauth url for the self-managed setup.

When should this change go live?

• This change is not yet live and should not be merged until {ADD_DATE} (apply hold label or convert to draft PR)?
• There is no urgency with this change.
• This change or page is part of a marketing blog, conference talk, or something else on a schedule.
• This functionality is already available but undocumented.
• This is a bug fix or security concern.

PR Checklist

• I have added changes to the relevant /versioned_docs directory, or they are not for an already released version.
• I have added changes to the main /docs directory (aka /next/), or they are not for future versions.
• My changes require an Engineering review, and I've assigned an engineering manager or tech lead as a reviewer, or my changes do not require an Engineering review.
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[akeller]

@camunda/modeling-dev & @npepinpe (grabbing your names from here), can you have a look or assign a reviewer?

[nikku]

Good stuff. Stylistically I'd propose the keycloak URL as an example (as other providers are possible).

I believe this fixes #2237?

[jonathanlukas]

@nikku good catch I did not find this issue 😅 I accepted your suggestions. This will make the docs more future-proof as C8 could support more different identity providers ootb.

[nikku]

🎉 Great contribution 💪