Add agent-plugins to awesome-ai-plugins?

Hey! Flutter Agent Plugins gives coding agents official Flutter skills and a Dart MCP server to develop and manage Flutter apps. Useful if you'd rather delegate Flutter work to an agent.

We maintain [awesome-ai-plugins](https://github.com/hashgraph-online/awesome-ai-plugins). Would you be up for adding agent-plugins with a PR? You can [edit the README directly](https://github.com/hashgraph-online/awesome-ai-plugins/edit/main/README.md).

Suggested entry:

- [agent-plugins](https://github.com/flutter/agent-plugins) - Official Codex plugin bundling Flutter skills and a Dart MCP server so agents can develop and manage Flutter apps.

[Submission guidelines](https://github.com/hashgraph-online/awesome-ai-plugins/blob/main/CONTRIBUTING.md).

Abre el editor del README.md de awesome-ai-plugins enlazado y lee primero las directrices de envío de CONTRIBUTING.md. Añade la entrada sugerida de agent-plugins en la sección correspondiente y, después, envía un PR; se considera terminado cuando la entrada está presente y sigue las directrices del repositorio.

Escrito por el modelo de indexación a partir del texto del issue.