Refactoring and add more docstrings

[mwong009]

Checklist

• There is an informative high-level description of the changes.
• The description and/or commit message(s) references the relevant GitHub issue(s).
• pre-commit is installed and set up.
• The commit messages follow these guidelines.
• The commits correspond to relevant logical changes, and there are no commits that fix changes introduced by other commits in the same branch/BR.
• There are tests covering the changes introduced in the PR.

Features

• NA

Fixes

• NA

Documentation

• Improved docstrings and other documentation

Maintenance

• refactor: clean up and enhance code with codiumAI

[codecov]

Codecov Report

Merging #91 (c2df619) into master (eb0322a) will increase coverage by 1.56%.
Report is 10 commits behind head on master.
The diff coverage is 36.86%.

Additional details and impacted files

@@            Coverage Diff             @@
##           master      #91      +/-   ##
==========================================
+ Coverage   52.26%   53.82%   +1.56%     
==========================================
  Files          17       17              
  Lines        1722     1789      +67     
==========================================
+ Hits          900      963      +63     
- Misses        822      826       +4     

Files	Coverage Δ
pycmtensor/functions.py	92.68% <ø> (ø)
pycmtensor/logger.py	91.17% <ø> (-0.26%)	⬇️
pycmtensor/models/layers.py	92.39% <ø> (ø)
pycmtensor/regularizers.py	100.00% <100.00%> (+6.25%)	⬆️
pycmtensor/statistics.py	100.00% <ø> (+77.35%)	⬆️
pycmtensor/utils.py	100.00% <100.00%> (ø)
pycmtensor/dataset.py	96.36% <93.33%> (-0.89%)	⬇️
pycmtensor/models/MNL.py	84.21% <75.00%> (ø)
pycmtensor/models/TasteNet.py	34.95% <50.00%> (ø)
pycmtensor/optimizers.py	21.51% <33.33%> (ø)
... and 4 more

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