Add README.md with full project documentation

[Copilot]

The repo had only a one-liner README with no setup guidance, architecture context, or access control documentation.

Changes

• Overview & architecture — ASCII diagram showing how Technic Launcher, Pterodactyl Panel, and Cloudflare Zero Trust interact; explains the core premise (delegate server management without root/SSH)
• Prerequisites table — quick-reference for required tools with links to official docs
• Setup guide — step-by-step instructions for each of the three components:
  • Pterodactyl Panel installation, egg selection, and scoped user permissions
  • Technic Solder/static host setup and Technic Platform modpack entry
  • Cloudflare Tunnel creation and Zero Trust Access Application configuration
• Usage — separate guidance for players, server managers, and modpack maintainers
• Security notes — highlights no-root-access guarantees and instant-revoke via Cloudflare policy removal

Original prompt

Build README.md based on this description of project:
I needed simple solution that could host server and modpack client but give someone the tools to manage it without giving him root access.
tools made for techniclauncher, pterodactyl panel
access managed by cloudflare zero trust