Two declarations were wrong for the repositories that consume this.

`engines` demanded Node 22, but four of the six plugins pin 18 and their CI
runs it. Nothing here needs 22.

`stylelint` and `@wordpress/stylelint-config` were listed as peers with narrow
ranges, and that turned into an ERESOLVE failure on a checkout still carrying
stylelint 14 through `@wordpress/scripts`. Neither is ever required by this
package — stylelint resolves the `extends` target from the consumer — so they
are gone from the manifest and documented in the README instead.

What remains as a peer is what the code actually loads or spawns.