Docs #106/15: ADR-0038 — Record pivot from MkDocs to Sphinx + PyData Sphinx Theme

[DEVunderdog]

Parent

#106

What to build

Write docs/adr/0038-sphinx-pydata-theme-replaces-mkdocs.md recording the decision to replace MkDocs 1.x + mkdocstrings with Sphinx + PyData Sphinx Theme + sphinx.ext.napoleon.

The ADR must capture:

• Decision: migrate the docs build toolchain from MkDocs + mkdocstrings to Sphinx + PyData Sphinx Theme + MyST-Parser + sphinx.ext.napoleon
• Rationale: MkDocs 1.x is abandoned upstream; MkDocs 2.0 removes the plugin system entirely, breaking mkdocstrings and mkdocs-material with no migration path; Sphinx is the Python ecosystem standard governed by NumFOCUS and used by NumPy, pandas, and scikit-learn — the same ecosystem DataForgeML targets
• What stays the same: numpy-style docstring format and scope rules from ADR-0034 remain fully in force — sphinx.ext.napoleon reads numpy-style docstrings natively, so no docstring rewrites are required
• What changes: build toolchain only — mkdocs.yml → docs/conf.py, mkdocstrings ::: directives → Sphinx autoclass/autofunction directives, mkdocs serve → sphinx-autobuild

Also add a one-line "Superseded by ADR-0038 (toolchain only — docstring rules unchanged)" note to docs/adr/0034-documentation-strategy-docstrings-mkdocs.md.

Acceptance criteria

• docs/adr/0038-sphinx-pydata-theme-replaces-mkdocs.md exists with decision, rationale, and scope of change
• ADR-0034 has a "Superseded by ADR-0038 (toolchain only)" note at the top
• ADR-0038 explicitly states numpy-style docstring format and scope rules are unchanged

Blocked by

None — can start immediately