support gatsbyjs-v3

[tonitrnel]

mainly modify the issuer property.

documentation on Webpack5 issuer property.
https://webpack.js.org/configuration/module/#ruleissuer

[coreyward]

Thanks for jumping on this! Is there a way to maintain support for pre-3.0 Gatsby with the same codebase?

[tonitrnel]

The versions of other GatsbyJS plugin packages have been upgraded from 2.x.x to 3.x.x, I think changing the package version number to 3.x.x can clearly indicate support for GatsbyJS V3

[kaishin]

Came looking for this. Great work @piecego!

[coreyward]

I've published this as v3.0.0-beta.0 for the time being so anybody on Gatsby v3 can give this a whirl without blocking on a solution that will allow us to maintain compatibility with Gatsby v2. This is something that I'd consider a very high priority since v2 has been out in the wild for over 2 years and likely has millions of installs, and the tendency with JS packages is to simply yarn add x instead of specifying a particular version range per-package, especially for plumbing like gatsby-plugin-svgr.

[coreyward]

Hey @piecego, I'm going to re-open this since it hasn't been merged in yet. 😄

[K20shores]

Will this be merged?