Modernize, containerize the hat bot

[Milkshak3s]

Changes

• Adds a requirements.txt with up-to-date packages
• Updates discord lib usage in line with current APIs
• Adds a Dockerfile for container-based deployment
• Adds a config.py for configuration via env vars
• Adds a GitHub Actions workflow for automated Docker image building & publishing

[qu-gg]

LGTM, Crimmis shall live on 🐧
It may need some tweaking based on Discord Bot rules as they have changed significantly recently.
Needs some validation and an application to host or something similar.

[Milkshak3s]

Extremely cool. We may need to modify intents/permissions for the bot btw, I just gave it default here.