docs: adding some info for getting multiple compose running

[germa89]

Description

As the title

Issue linked

NA

Checklist

• I have visited and read Develop PyMAPDL.
• I have tested my changes locally
• I have added necessary documentation or updated existing documentation.
• I have followed the PyMAPDL coding style guidelines.
• I have added appropriate unit tests that also ensure the minimal coverage criteria.
• I have reviewed my changes before submitting this pull request.
• I have linked the issue or issues that are solved to the PR if any.
• I have assigned this PR to myself.
• I have marked this PR as draft if it is not ready to be reviewed yet.
• I have made sure that the title of my PR follows Commit naming conventions (e.g. feat: adding new MAPDL command)

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[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 86.97%. Comparing base (93f9906) to head (c513da7).
Report is 2 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3584      +/-   ##
==========================================
- Coverage   86.98%   86.97%   -0.01%     
==========================================
  Files         187      187              
  Lines       14623    14623              
==========================================
- Hits        12720    12719       -1     
- Misses       1903     1904       +1     

[germa89]

I'm not waiting for the CICD since this is not check by it.

@pyansys-ci-bot LGTM.

[pyansys-ci-bot]

✅ Approving this PR because germa89 said so in here 😬