Doc work and sandbox previews

• As tracked on issue 1041, we will be transitioning content rendering to Quarto. Meanwhile, though, we can check rendering using sphinx (for Python) and pkgdown (for R).
• sphinx instructions:
  • cd to the repo base (not apis/python)
  • It won't pick up editable installs. Therefore after each sandbox edit you must do pip uninstall -y tiledbsoma && pip install apis/python
  • Run doc/sandbox-gen.sh
  • Open doc/html/index.html
  • Iterate
• pkgdown instructions:
  • cd to apis/r (not the repo base)
  • R CMD INSTALL --no-byte-compile --no-test-load --no-docs --no-html .
  • Within R: pkgdown::build_site()
  • Open docs/index.html
  • Iterate