fix: fix build error with import uris

[victorlcm]

Hey everyone,

I'm using this template for coding some libraries for my k6 tests and I've encountered an issue while trying to build when using imports from URIs like

import { randomIntBetween } from 'https://jslib.k6.io/k6-utils/1.1.0/index.js';

This PR aims to fix that by adding core-js and changing the external regex in webpack.config.js to anything that includes k6.

I've also included some scripts build and watch to improve developer experience

[victorlcm]

Hey guys, can anyone help me with a review in this one? I could not add reviewers by editing the PR, sorry! @ppcano, @simskij

[ppcano]

Hi Victor,

thank you for the PR and research on this issue.

I think it should be fixed by b4b8dee. Please, let me know otherwise.

Related issue #16

I've also included some scripts build and watch to improve developer experience

I rather let this project as a basic template to avoid being opinionated and let everyone extend on their own.