Enabled use with NPM

[gfortaine]

cc @abenevaut

[abenevaut]

Hello! Thanks for the PR, i'm very interested to be able to use this stuff as npm vendor.
@gfortaine could you please add detailed description to allow maintenairs (@nayuki @scrpi @0-wiz-0) to correctly understand which need you fill with this PR, and (if required) explains actions that maintenairs will have to do to publish the package (maybe advice a workflow to publish the package automatically on npm).

[abenevaut]

@gfortaine namespace should probably decided with maintenairs.

[nayuki]

Sorry, committing thousands of lines of auto-generated, unauditable configuration files (.pnp.js, yarn.lock) is unacceptable.