fix: Set correct peerDependency on gatsby

[LekoArts]

Hello @jariz @JoshuaWalsh, Gatsby maintainer here 👋

While looking at your plugin I noticed that the peerDependency on gatsby is set incorrectly. We're in the process of providing more helpful information on the /plugins page of our website and for that we need plugins to set their peerDependencies correctly/more specific.

At the moment you say that any version (v3, v4, v5, v6, etc.) will work with this even when in between we'd introduce breaking changes.

Making it more explicit is the safer choice (in the future you'll be able to mark breaking changes with explicit version ranges) and will allow us to display the plugin as compatible to versions X, Y, Z.

Thanks!

[YoshiWalsh]

Hi @LekoArts ,

Thanks very much. I believe that our plugin does work on all currently released versions of Gatsby above >2.0.0-alpha, but obviously we can't guarantee that a breaking change in future won't cause issues.

We're having some issues with our automated tests at the moment, they seem to be caused by an issue with Snyk. I know that changing peerDependency shouldn't have an effect on the test results, but I'd like to fix the issue with our tests before I merge this PR.

While you're here, would you mind taking a look at gatsbyjs/gatsby#27988 for us? We need a response from the Gatsby Core team in order to proceed.

Thanks, Josh

[LekoArts]

No problem!

I've resurfaced this internally and will see that you get an answer :)