DOC: Add info about incremental algorithms and BS (#2103)

[olegkkruglov]

• Add 'Non-Scikit algorithms' part to the docs
• Add info about IncrementalPCA
• Add sphinx.napoleon extension to generate docs from docstrings.
• Update docstrings for non-scikit algorithms

Description

Add a comprehensive description of proposed changes

List associated issue number(s) if exist(s): #6 (for example)

Documentation PR (if needed): #1340 (for example)

Benchmarks PR (if needed): IntelPython/scikit-learn_bench#155 (for example)

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Checklist to comply with before moving PR from draft:

PR completeness and readability

• I have reviewed my changes thoroughly before submitting this pull request.
• I have commented my code, particularly in hard-to-understand areas.
• I have updated the documentation to reflect the changes or created a separate PR with update and provided its number in the description, if necessary.
• Git commit message contains an appropriate signed-off-by string (see CONTRIBUTING.md for details).
• I have added a respective label(s) to PR if I have a permission for that.
• I have resolved any merge conflicts that might occur with the base branch.

Testing

• I have run it locally and tested the changes extensively.
• All CI jobs are green or I have provided justification why they aren't.
• I have extended testing suite if new functionality was introduced in this PR.

Performance

• I have measured performance for affected algorithms using scikit-learn_bench and provided at least summary table with measured data, if performance change is expected.
• I have provided justification why performance has changed or why changes are not expected.
• I have provided justification why quality metrics have changed or why changes are not expected.
• I have extended benchmarking suite and provided corresponding scikit-learn_bench PR if new measurable functionality was introduced in this PR.

[samir-nasibli]

fails in this PR is not related with the changes.
Already resolved for the main branch with test deselections.
Could be ignored in the scope of this PR validation

[samir-nasibli]

@maria-Petrova here only docstrings are changed do we need to run internal CI?

[maria-Petrova]

@samir-nasibli, doc build in public CI is sufficient. Why condaEnv steps are failing?

[samir-nasibli]

Potentially this changes dependend on the PR #2038
I am not sure what is better partially bring those changes here, for BS attr renaming I mean or just update docstrings for the 2025.0 BS impl. From my prospective the second one more safe.
@maria-Petrova @icfaust I would like to know your opinions as well

Fails should be addressed

[samir-nasibli]

@samir-nasibli, doc build in public CI is sufficient. Why condaEnv steps are failing?

I have already comment out, but now it comes to me that my prev comment #2112 (comment) is not correct. I see fails, that already should be addressed on 2025.0 rls branch with the latest commits there.
@Vika-F @ethanglaser any thoughts?

[ethanglaser]

It should be merged, but would prefer to merge via backport PR (#2114 )

[samir-nasibli]

@olegkkruglov what is the status?