npm run create-day 5 to create the source file for December 5th.
npm run create-today to create the source file for today.
This is based on scripts/day.template.
You could edit this to import common utils from src/utils.ts.
npm run day 05 runs webpack with typescript loader over src/05.ts to produce a bundle in dist/05.js, then runs it.
npm run today runs the same as above but for today and it watches for changes.
You can also run npm run watch-day 5 to run December 5th's file while watching for changes.
I wanted the bundling so I can copy/paste to share my solution in the Slack channel at work. The webpack bundle output isn't the easiest thing to influence and is by default quite ugly though :'(...