This ticket will kick-off a pilot implementation of pipelines documentation in Sphinx. Specific goals are
1. Develop template for sphinx-ready doc/ directories in packages (based on SQR-006)
2. Setup a MVP sphinx template that works well with numpydoc and astropy automodsumm. Simply porting astropy’s sphinx template would be pragmatic.
3. documenteer-driven configuration for sphinx.
These will be MVPs, and iterated upon in later tickets that implement sphinx API docs for stack packages.