Improve template compilation/build process

[abraham]

Having a multi-step build process adds complexity and making changes more difficult. Maybe there is a better approach that will simplify tooling and improve developer experience.

Some options:

• Move all the nunjucks variables into runtime
  • Ships more code to the client as features would be enabled/disabled during render
  • Makes enabling and disabling features with database changes easier
• Switch to webpack
  • Webpack is awesome but also terrible
  • Can keep nunjuck and use it as a step during build
  • There is a PWA Starter Kit example https://github.com/Polymer/pwa-starter-kit/tree/webpack
• TypeScript json
  • Probably some way of importing the config json and having compilation logic with TS
• Rollup
• Something else

[abraham]

This is mostly improved with #579. es-dev-server and rollup now handle template compilation without needing an intermediate build step.