Feat: Add RFC 9116 compliant security.txt Cloudflare Worker Template

[MOBILEPHONE]

Hi Cloudflare Team,

I am submitting a community-driven, enterprise-grade template (security-txt-template) to help developers easily deploy RFC 9116-compliant vulnerability disclosure policies at the edge.

This is especially vital for developers hosting on static CMS platforms (such as Blogger, Shopify, Webflow, or Wix) where uploading custom files to the root /.well-known/ directory is restricted.

Features Included:

• ⚙️ Dynamic Auto-Expiration: Automatically calculates and updates the mandatory "Expires:" date to exactly 1 year in the future, making the file completely maintenance-free.
• 🔐 Dual Route Serving: Supports serving both your raw security policy (/.well-known/security.txt) and its cryptographic PGP signature (/.well-known/security.txt.sig) natively.
• 🌐 Global CORS & Security Headers: Enforces wildcard CORS headers, allowing automated global compliance scanners and vulnerability crawlers to parse your security files cleanly without being blocked by browser-level cross-origin security policies.

I have fully validated, tested, and formatted this template locally inside our development environments. I look forward to your review and feedback!