use `qrcode-generator` as package dependency?

[sabrinaluo]

Hello, thank you for the amazing qart.

Wondering if it's possible to use https://www.npmjs.com/package/qrcode-generator as dependency rather than including qrcode.js in the bundle? or maybe expose qrcode API ?

The situation I encountered is to need both API of qart and qrcode, since qart didn't expose the qrcode API, will need to install the origin qrcode-generator. This makes the bundle size bigger than it should. :)

[misteral]

@sabrinaluo Hi, please welcome pull request. @kciter what u think(do we have any changes in local version) ?