feat: add Unified REST API docs

[tmetzke]

Description

• Adds the Camunda 8 REST API as a new item in the APIs and tools, "deprecated" component APIs are removed
  
• Adds the Camunda 8 REST API as a new item in the API sidebar, "replaced" component APIs are moved to deprecated section
  
• Adds all v1 endpoints of the Zeebe REST API to the Camunda 8 REST API and adds the job activation endpoint
  

closes #3918

When should this change go live?

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

PR Checklist

• My changes are for an already released minor and are in /versioned_docs directory.
• My changes are for the next minor and are in /docs directory (aka /next/).
• I included my new page in the sidebar file(s).
• I added a redirect for a renamed or deleted page to the .htaccess file.

• My changes require an Engineering review, and I've assigned the Engineering DRI or delegate.
• My changes require a technical writer review, and I've assigned @camunda/tech-writers as a reviewer.

[github-actions]

👋 🤖 🤔 Hello! Did you make your changes in all the right places?

These files were changed only in docs/. You might want to duplicate these changes in versioned_docs/version-8.5/.

• docs/apis-tools/camunda-api-rest/camunda-api-rest-authentication.md
• docs/apis-tools/camunda-api-rest/camunda-api-rest-overview.md
• docs/apis-tools/camunda-api-rest/sidebar-schema.js
• docs/apis-tools/camunda-api-rest/specifications/activate-jobs.api.mdx
• docs/apis-tools/camunda-api-rest/specifications/assign-a-user-task.api.mdx
• docs/apis-tools/camunda-api-rest/specifications/camunda-8-rest-api.info.mdx
• docs/apis-tools/camunda-api-rest/specifications/complete-a-user-task.api.mdx
• docs/apis-tools/camunda-api-rest/specifications/get-cluster-topology.api.mdx
• docs/apis-tools/camunda-api-rest/specifications/sidebar.js
• docs/apis-tools/camunda-api-rest/specifications/unassign-a-user-task.api.mdx
• docs/apis-tools/camunda-api-rest/specifications/update-a-user-task.api.mdx
• docs/apis-tools/working-with-apis-tools.md

You may have done this intentionally, but we wanted to point it out in case you didn't. You can read more about the versioning within our docs in our documentation guidelines.

[akeller]

Added @pepopowitz for a DX review since this incorporates updates to the API reference docs via integrated explorer.

[akeller]

@tmetzke 👀 did this go live... today?

[tmetzke]

@tmetzke 👀 did this go live... today?

No, this was merged after the 8.6.0-alpha2 code freeze, so it will officially come with alpha3.

[akeller]

Per an internal conversation, @aleksander-dytko proposes we launch this as "Camunda 8 REST API" instead of "Unified REST API".

@tmetzke can you update this PR? And any supporting assets to reflect this name?

[tmetzke]

Per an internal conversation, @aleksander-dytko proposes we launch this as "Camunda 8 REST API" instead of "Unified REST API".

@tmetzke can you update this PR? And any supporting assets to reflect this name?

Adjusted the PR and the (internal) endpoint definition document.

[christinaausley]

@tmetzke This looks good text-wise.

• Once this goes live, I'll add to Postman.
• Will a tutorial also be incorporated, or are you looking for assistance from the DX team?

[tmetzke]

@tmetzke This looks good text-wise.

• Once this goes live, I'll add to Postman.
• Will a tutorial also be incorporated, or are you looking for assistance from the DX team?

I wasn't aware that we have such a thing, I just looked at the existing tutorial now.
With the component APIs becoming unified in the C8 REST API, we should create one unified tutorial, too. It can cover different aspects, e.g. two different sections on specifics to tasks and process instances. However, the general setup and authentication would be equal since it's one API.

[akeller]

🌟 Bonus points for assisting with the other cleanup 🏆

[tmetzke]

@akeller, ready for merge from my end (couldn't remember if I hit squash and merge or if your team does it 😄)

[akeller]

@tmetzke We are in this weird limbo period ahead of the release. You can merge this but risk releasing it if we need to do any releases before next week. If this is not a risk, you can merge.

[tmetzke]

@tmetzke We are in this weird limbo period ahead of the release. You can merge this but risk releasing it if we need to do any releases before next week. If this is not a risk, you can merge.

My most beloved phase of each month. Well, it would be a sneak peak at worst and the artifacts are also already built and released, so 🤷 You cannot access it in SaaS yet but it's also on Next. I'd assume we can live with this.

[akeller]

YOLO let's go

[christinaausley]

@tmetzke This looks good text-wise.

• Once this goes live, I'll add to Postman.
• Will a tutorial also be incorporated, or are you looking for assistance from the DX team?

I wasn't aware that we have such a thing, I just looked at the existing tutorial now. With the component APIs becoming unified in the C8 REST API, we should create one unified tutorial, too. It can cover different aspects, e.g. two different sections on specifics to tasks and process instances. However, the general setup and authentication would be equal since it's one API.

@tmetzke I'll add an issue to my backlog to create a tutorial for this, and I'll get this added to Postman next Tuesday 😄