Add Read the Docs configuration

- Add .readthedocs.yaml configuration file for RTD builds
- Update docs/doc_requirements.txt with comprehensive dependencies
- Include all necessary packages for documentation build
- Configure Python 3.9 and Ubuntu 22.04 for RTD environment

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

Author: jeremymanning

.readthedocs.yaml

@@ -0,0 +1,28 @@
+# .readthedocs.yaml
+# Read the Docs configuration file
+# See https://docs.readthedocs.io/en/stable/config-file/v2.html for details
+
+# Required
+version: 2
+
+# Set the version of Python and other tools you might need
+build:
+  os: ubuntu-22.04
+  tools:
+    python: "3.9"
+    # You can also specify other tools here or in a separate tools block
+
+# Build documentation in the docs/ directory with Sphinx
+sphinx:
+   configuration: docs/conf.py
+
+# If using Sphinx, optionally build your docs in additional formats such as PDF
+# formats:
+#    - pdf
+
+# Optionally declare the Python requirements required to build your docs
+python:
+   install:
+   - method: pip
+     path: .
+   - requirements: docs/doc_requirements.txt

docs/doc_requirements.txt

@@ -1,8 +1,20 @@
-sphinx==2.3.0
-sphinx_bootstrap_theme==0.6.4
-sphinx-gallery
-numpydoc
+sphinx>=4.0.0
+sphinx_bootstrap_theme>=0.7.0
+sphinx-gallery>=0.10.0
+numpydoc>=1.1.0
 deepdish
-nbsphinx
-jupyter_client
+nbsphinx>=0.8.0
+jupyter_client>=6.0.0
 wikipedia
+ipython
+# Main package dependencies
+PPCA>=0.0.2
+scikit-learn>=1.4.0
+pandas>=2.2.0
+seaborn>=0.13.0
+matplotlib>=3.8.0
+scipy>=1.13.0
+numpy>=2.0.0
+umap-learn>=0.5.5
+requests>=2.31.0
+ipympl>=0.9.3