CHANGELOG for @apollo/composition

This CHANGELOG pertains only to Apollo Federation packages in the 2.x range. The Federation v0.x equivalent for this package can be found here on the version-0.x branch of this repo.

2.3.0

2.3.0-beta.2

• Error on composition when a @shareable field runtime types don't intersect between subgraphs: a @shareable field
  must resolve the same way in all the subgraphs, but this is impossible if the concrete runtime types have no
  intersection at all PR #1556.
• Uses the 0.3 version of the tag spec in the supergraph, which adds @tag directive support for the SCHEMA location PR #2314.
• Fixes composition issues with @interfaceObject PR #2318.

2.3.0-alpha.0

• Preserves source of union members and enum values in supergraph PR #2288.
• BREAKING: composition now rejects @override on interface fields. The @override directive was not
  meant to be supported on interfaces and was not having any impact whatsoever. If an existing subgraph does have a
  @override on an interface field, this will now be rejected, but the @override can simply and safely be removed
  since it previously was ignored.