update docstring for harmony

[Intron7]

Align docstring from rapids-singlecell and scanpy for harmony

[codecov-commenter]

Codecov Report

❌ Patch coverage is 66.66667% with 1 line in your changes missing coverage. Please review.
✅ Project coverage is 88.03%. Comparing base (8ec14dc) to head (4b9ba8d).
⚠️ Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
...pids_singlecell/preprocessing/_harmony/__init__.py	66.66%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #647      +/-   ##
==========================================
- Coverage   88.04%   88.03%   -0.01%     
==========================================
  Files          96       96              
  Lines        7032     7035       +3     
==========================================
+ Hits         6191     6193       +2     
- Misses        841      842       +1     

Files with missing lines	Coverage Δ
...ids_singlecell/preprocessing/_harmony_integrate.py	57.50% <ø> (ø)
...pids_singlecell/preprocessing/_harmony/__init__.py	93.67% <66.66%> (-0.48%)	⬇️