docs: update docker instructions

[germa89]

Description

As the title.

Issue linked

Close #3579

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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[wiz-inc-572fc38784]

Wiz Scan Summary

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[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 86.98%. Comparing base (aad1006) to head (f2b599f).
Report is 1 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #3580   +/-   ##
=======================================
  Coverage   86.98%   86.98%           
=======================================
  Files         187      187           
  Lines       14623    14623           
=======================================
  Hits        12720    12720           
  Misses       1903     1903           

[germa89]

Please @moe-ad can you have a look and see if this PR mitigates your issues?

[germa89]

@pyansys-ci-bot LGTM.

[pyansys-ci-bot]

✅ Approving this PR because germa89 said so in here 😬

[germa89]

Because @moe-ad is going to test again with WSL and the new docs, let's merge this and we can always edit accordingly.