[dsherret]

The `deno cache` command (ex. `deno cache main.ts` or `deno cache --node-modules-dir main.ts` if you want a node_modules folder) will ensure all npm packages used in the provided module are cached ahead of time. It acts similarly to a `npm install` if you need it.

Also, at the moment, npm specifiers aren't supported with `deno compile` (https://deno.land/manual@v1.28.0/tools/compiler), but in the future that will be one way to have a self contained executable with everything ready to go.