feat!: support rollup v3

[pi0]

Resolves #226

• Update transform outputOptions for v3 compatibility
• Update rollup peerDependency to 3.0.0 (options API is changed)
• Add json assertion to package.json import

[Swatinem]

CI is not too happy. It needs to bump the lower node version. Also there is a bunch of snapshot changes, but those seem to be related to some more comments in the output. I can check all that stuff maybe on the weekend.

[Mister-Hope]

Btw, can we add tests for 14 and 16? That may perform a more accurate result.Also Node 12 should be dropped

[SukkaW]

CI is not too happy. It needs to bump the lower node version.

Rollup has bumped the minimum required Node.js version to 14 as part of its breaking changes.

If rollup-plugin-dts is going to adopt this change, a new major version has to be released.

[Swatinem]

I manually merged this, fixed up all the tests, and bumped the minimum supported rollup and node versions.

can we add tests for 14 and 16?

I rather just want to test with latest node and minimum supported, I don’t think testing intermediate versions provides any value.

I will publish a new major in the coming days.