Declare Asset Packagist composer repo and config

It would be helpful if Commerce did the work to become compatible with Asset Packagist so that all the modules in the ecosystem could rely on it. For example, we need a jQuery plugin in the POS Receipt module. I propose we use the same repo and config and composer script that Lightning uses - http://lightning.acquia.com/blog/round-your-front-end-javascript-librari....

Would the repo and config go into https://github.com/drupalcommerce/project-base/blob/8.x/composer.json? I'm happy to submit a patch or PR.