A new Community-Written Solution for setting up a community mirror

[SavaLione]

This adds a new new community-written solution for setting up a community mirror.

Go Mirror Zig is a simple way to set up a Zig community mirror.
It is lightweight, distributed as a single binary and supports automatic ACME challenges.

Features:

• Efficient caching: Downloads files from an upstream server once and serves them from a local cache for all subsequent requests.
• Automatic TLS: Full support for ACME (Let's Encrypt) to automatically obtain and renew TLS certificates.
• Secure by default: Supports HTTPS and automatic redirection from HTTP to HTTPS.
• Standalone binary: Compiles to a single, dependency-free binary for easy deployment.
• Configurable: All settings are manageable via command-line flags, including ports, cache directories, and upstream URL.
• Path correctness: Caches files using the official Zig directory layout (/download/<version>/ and /builds/).

The solution source code: https://github.com/SavaLione/go-mirror-zig/

Thanks!