Major documentation overhaul for binary serialization and SignalR:
- Simplified and clarified AyCode.Core README, with direct links to new deep-dive docs (BINARY_IMPLEMENTATION.md, BINARY_WRITERS.md)
- Added BINARY_WRITERS.md: detailed design and rationale for ArrayBinaryOutput and BufferWriterBinaryOutput, chunk sizing, and buffer management
- Refined BINARY_IMPLEMENTATION.md: clearer buffer management, output strategies, and hot-path rules; references new writers doc
- Added SIGNALR_BINARY_PROTOCOL.md: full wire format, zero-copy pipeline, dual BWO pattern, and read path for custom SignalR protocol
- Updated SignalRs README and SIGNALR.md: clarified protocol, tag system, request/response flow, and technical debt
- Improved cross-linking and discoverability throughout
These changes make the technical documentation clearer, more maintainable, and easier to navigate for advanced contributors.
