[skip ci]
* chore: switch to yarn BREAKING CHANGE: Pinafore is now using yarn rather than npm, so those who self-host will need to stop running e.g. `npm install` and run `yarn install` instead. * install latest yarn
* Added Dockerfile * Better comments in Dockerfile * Added SIGINT handler * Keeping code-check happy * Keeping code-check happy v2 * Keeping code-check happy v2