Add to acp-registry

[Jengro777]

https://github.com/agentclientprotocol/registry

https://zed.dev/blog/acp-registry

[1716775457damn]

Good idea - adding claw-code to the ACP registry would improve discoverability for agent clients. Before submitting a PR to agentclientprotocol/registry, we should verify the project meets listing requirements (stable protocol, docs, ACP spec compliance). Worth reviewing the registry contribution guide first.