docs: add geometry preparation for Fluent simulation

[RobPasMue]

Description

Follow up of current NACA airfoil example

Issue linked

None

Checklist

• I have tested my changes locally.
• I have added necessary documentation or updated existing documentation.
• I have followed the coding style guidelines of this project.
• I have added appropriate unit tests.
• 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 added the minimum version decorator to any new backend method implemented.
• I have made sure that the title of my PR follows Conventional commits style (e.g. feat: extrude circle to cylinder)

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 90.59%. Comparing base (c807809) to head (2ca253c).

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #1183   +/-   ##
=======================================
  Coverage   90.59%   90.59%           
=======================================
  Files          93       93           
  Lines        7015     7015           
=======================================
  Hits         6355     6355           
  Misses        660      660           

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