🎉 First public release of Cap'n Web Rust implementation!

Features:
- Core protocol implementation with capability-based security
- Multiple transport layers (HTTP batch, WebSocket, WebTransport)
- Production-ready server with rate limiting
- High-performance client with batching and pipelining
- Full TypeScript interoperability
- Comprehensive documentation and examples

This release includes:
- capnweb-core: Core protocol types and wire format
- capnweb-transport: Transport layer implementations
- capnweb-server: Production server with capability management
- capnweb-client: High-performance client with batching