Fix JupyterBook 2.0 documentation build on GitHub Pages #92

Problem

The documentation build is failing on GitHub Pages with JupyterBook 2.0 due to R/rpy2 import errors in the notebooks.

Error

Error importing in API mode: ImportError

This occurs because:

1. GitHub Actions doesn't have R installed by default
2. The notebooks try to import rpy2 directly without proper error handling
3. JupyterBook 2.0 has stricter notebook execution requirements

Solution

Options to fix:

1. Update all notebooks to gracefully handle missing R/rpy2
2. Install R in the GitHub Actions workflow
3. Use the Python-only implementation (see Replace R/rpy2 dependency with py-statmatch once ready #93)

Affected notebooks

• docs/models/matching/matching-imputation.ipynb
• docs/models/qrf/qrf-imputation.ipynb
• docs/autoimpute/autoimpute.ipynb
• docs/models/quantreg/quantreg-imputation.ipynb
• docs/models/ols/ols-imputation.ipynb
• docs/imputation-benchmarking/benchmarking-methods.ipynb