Introducing lua-capnproto: better serialization in Lua

Introduced lua-capnproto, a new open-source Lua module for Cap'n Proto serialization and deserialization. This module provides high-performance data transfer capabilities for Lua applications, addressing the need for efficient serialization within Cloudflare's NGINX/Lua stack and for inter-data center communication. The post details installation, Cap'n Proto definition, data preparation, and usage examples for serialization and deserialization, along with performance comparisons to lua-cjson.