Improving HTML Time to First Byte

Introduced a zero-config edge caching mechanism for HTML using HTTP headers (`x-HTML-Edge-Cache`). This allows origins to communicate caching rules (e.g., `cache`, `bypass-cookies`) and purge commands (`purgeall`) to Cloudflare's edge nodes without requiring explicit API integration or configuration. A companion Worker script and WordPress plugin demonstrate the implementation, leveraging Workers KV for global cache versioning and purging.