The marketplace index can now carry plugins of other publishers, published
from their authors' repositories through the l0ng-ai/openidea-plugins
registry.
- `openidea-plugin index` with a key replaces only that publisher's plugins
(it used to drop every other entry); without a key it indexes each package
against the publishers the index already lists, checking the key and the
id prefix instead of only the signature itself.
- `openidea-plugin merge` takes another index's publishers, plugins and
revocations in place of every publisher but `--keep`; the other index can't
list or revoke the kept publishers' plugins.
- `openidea-plugin check` accepts a `.oiplugin` file.
- Releases merge the registry's index into plugins-index.json and attach the
Linux x64 tool; plugins-index.yml refreshes the community plugins in the
latest release hourly or when the registry signals a change.
- plugins/README.md and CONTRIBUTING.md describe official and community
plugins.
