Update README + docs landing for recent releases

[kgdunn]

Summary

Update the front-facing docs so they catch up with the last few weeks of releases (through v1.55.0) and read in a way that makes a prospective user want to try the package right away.

• README: new "What's new" section; expanded feature list and comparison table (adaptive/on-line monitoring, OMARS & optimal DOE); new runnable quick-start snippets for AdaptivePCA on-line monitoring and for OMARS / D-optimal designs.
• Softened the scikit-learn framing from an adversarial "Why not scikit-learn?" to a complementary "Works alongside scikit-learn", per maintainer preference.
• Removed the factori.al references.
• Dropped the in-memory/scaling caveat callout from the README front page.
• Wording: reserve "batch" for the batch-process data sense used elsewhere in the repo; the adaptive-model context now uses "static"/"initial"/"offline" instead.
• Docs landing/quickstart updated to mirror the new highlights.
• Version bumped to 1.55.1 with a matching CITATION.cff update and a CHANGELOG.md Documentation entry.

Test plan

• New README/quickstart snippets were executed against the real API: AdaptivePCA().fit().update(), AdaptivePLS().fit(), generate_design(..., design_type="omars"/"d_optimal"), and evaluate_design(..., metric="all") all run.
• No em-dashes introduced in the edited docs.
• pyproject.toml and CITATION.cff report the same version.

Checklist

• Version bumped in pyproject.toml (PATCH for docs)
• Tests added or updated where relevant (docs-only change; not applicable)
• ruff check . passes
• CHANGELOG.md updated

🤖 Generated with Claude Code

https://claude.ai/code/session_01X762hoccCvqtJuDgwUf6BH