Added docstrings for all exported methods!

[anurag-mds]

This PR addresses issue #533 by ensuring that all exported methods in TimeSeries.jl have comprehensive docstrings.


The following actions were taken:

Reviewed all exported functions, types, and constants.
Added or improved docstrings for any missing or incomplete documentation.
Followed the existing documentation style for consistency.
Included examples where helpful.

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Motivation:

Having complete docstrings for all exported methods improves usability and discoverability for users, making the package easier to use and understand.

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Notes:

All existing tests are passing. No change was done to code just documentation-only fixes were done.

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Reviewers:

@ValentinKaisermayer @iblislin

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 85.58%. Comparing base (3291223) to head (90a0372).
⚠️ Report is 16 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #545      +/-   ##
==========================================
+ Coverage   85.44%   85.58%   +0.14%     
==========================================
  Files          11       13       +2     
  Lines         625      888     +263     
==========================================
+ Hits          534      760     +226     
- Misses         91      128      +37     

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