Adding missing env variables for Spring SDK documentation

[ana-vinogradova-camunda]

Adding missing env variables for Spring SDK documentation

• for REST configuration
• for gRPC configuration

Closes: #4297

Description

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/).

• 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.

[akeller]

This looks like the path for Tasklist, but in the 8.5 docs I see 8080 for the Zeebe API. Can you help me understand this change?

[ana-vinogradova-camunda]

Hi @akeller , thank you for pointing that out.
The examples are from my local deployment where I mapped port 8080 to 8083 for REST.
8080 would be the port for the Zeebe API.

[ana-vinogradova-camunda]

I will make the change now.

[akeller]

Approving based on the discussion in the PR, but I can't test this. Given that this is an example, I think that's sufficient to merge.