chore: Release 0.2.0

[nfebe]

Version bump, and the changelog entry filled out. It was written before the
review and described only the original shape of the feature.

[sourceant]

Code Review Summary

✨ Release chore for 0.2.0. composer.json bumps the package version from 0.1.0 to 0.2.0, and CHANGELOG.md gains a fleshed-out entry for the offer providers feature: GET offers, POST offers/{provider} and DELETE offers/{provider}/{id} now answer to the configured owner the same way the mail template endpoints do, admin.offer_providers rejects classes that do not implement the contract and duplicate keys claimed by two providers, and admin.requests.create_offer lets a host validate a new discount its own way. The changelog text had been written before the review and described the feature's original shape, so it has been updated to match what the endpoints and configuration actually do. No code review findings were supplied with this change; the edits are limited to version metadata and documentation, with no runtime behaviour affected.

[sourceant]

Review complete. See the overview comment for a summary.

[sourceant]

Both bullets are grammatically awkward and hard to parse on a quick skim of the release notes. The first reads "...refused with a message when it names a class that does not implement the contract or two providers claiming one key", where the two rejection reasons are run together without parallel structure; the second uses "a host can ask for its own fields", which does not clearly say what the host is asking for. Rewording keeps the same technical content but makes the two failure modes and the request hook unambiguous.

Suggested change

	- `admin.offer_providers` configuration, refused with a message when it names a class that does not implement the contract or two providers claiming one key
	- `admin.requests.create_offer`, so a host can ask for its own fields when a discount is created
	+- `admin.offer_providers` configuration, rejected with a clear message when it names a class that does not implement the contract, or when two providers claim the same key
	+- `admin.requests.create_offer`, letting a host request its own fields when a discount is created

[sourceant]

Review complete. No specific code suggestions were generated. See the overview comment for a summary.