Add missing main call for example file

[alpertoygar]

Fixes # .

• Add missing main call for the example file

Summary/Motivation:

The missing main call in the example file prevents the running of the file properly. In accordance with the other example files the main call is added.

Changes proposed in this PR:

• Add missing main call for the example file

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[codecov]

Codecov Report

Attention: Patch coverage is 50.00000% with 1 line in your changes missing coverage. Please review.

Project coverage is 88.54%. Comparing base (a777d7a) to head (d354166).
Report is 112 commits behind head on main.

Files	Patch %	Lines
...les/reactor_design/parameter_estimation_example.py	50.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3349      +/-   ##
==========================================
+ Coverage   88.53%   88.54%   +0.01%     
==========================================
  Files         868      868              
  Lines       98504    98506       +2     
==========================================
+ Hits        87210    87224      +14     
+ Misses      11294    11282      -12     

Flag	Coverage Δ
linux	86.05% <50.00%> (-0.01%)	⬇️
osx	?
other	83.86% <50.00%> (-2.69%)	⬇️
win	83.86% <50.00%> (+<0.01%)	⬆️

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[alpertoygar]

Codecov Report

Attention: Patch coverage is 50.00000% with 1 line in your changes missing coverage. Please review.

Project coverage is 88.54%. Comparing base (a777d7a) to head (d354166).
Report is 110 commits behind head on main.

Files Patch % Lines
...les/reactor_design/parameter_estimation_example.py 50.00% 1 Missing ⚠️
Additional details and impacted files
☔ View full report in Codecov by Sentry. 📢 Have feedback on the report? Share it here.

I don't know if the main call itself should be tested. If it is tested per the codebase conventions can you please direct me to an example so that I can add it.