- Add index.d.ts with comprehensive type definitions for all exported classes
- Include type declarations for Connection, NodeJSSerialConnection, and other connection types
- Add types for Constants, Advert, Packet, BufferUtils, and CayenneLpp
- Add type declarations for submodules (constants, buffer_reader, buffer_writer)
- Update package.json to reference the types file
This enables TypeScript users to have proper type checking and autocomplete when using the library.
