Add sphinxbibtex and function to get references from methods

[rohanbabbar04]

Closes #640

• Add sphinxcontrib.bibtex to handle references.
• Add function to generate citations.

Description

Checklist

• Code style is correct (follows ruff and black guidelines)
• Includes new or updated tests to cover the new feature
• New features are properly documented (with an example if appropriate)

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 90.32258% with 3 lines in your changes missing coverage. Please review.

Project coverage is 74.32%. Comparing base (f25da81) to head (9688003).
Report is 108 commits behind head on main.

Files with missing lines	Patch %	Lines
preliz/internal/citations.py	88.00%	3 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #651      +/-   ##
==========================================
- Coverage   82.23%   74.32%   -7.92%     
==========================================
  Files         101      107       +6     
  Lines        8020     8805     +785     
==========================================
- Hits         6595     6544      -51     
- Misses       1425     2261     +836     

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[rohanbabbar04]

This DOI in mle looks broken.

[aloctavodia]

This is the correct one https://doi.org/10.1177/0049124104268644

[aloctavodia]

This should also work outside a notebook environment

[rohanbabbar04]

In that case, will it return a string of the references?

[aloctavodia]

yes, we should also have an option to write to a file

[rohanbabbar04]

I have added an option to write to a file, if no file path is provided we can just return the string