Improve templating

[rossbar]

The analysis page for each project is generated from a templated (markdown) notebook. The templating could use a lot of improvement:

• Makefile
  • Improve compat with default sphinx Makefile - either plug into "mode" mechanism or remove/replace mode mechanism entirely
  • Use Makefile vars (e.g. %) to clean up targets and not specify everything manually
  • Make the generated notebooks also depend on their corresponding data files
• Use an actual templating engine (e.g. jinja) instead of the home-cooked solution in site/tools/generate_from_template.py