Docker Improvements

[Sudo-Ivan]

Hello Liam,

I have made some improvements to the docker for better security, reproducibility and decreasing image size.

• Reduced Image size (switching to Alpine).
• Better supply chain security
• Version ARGs for easier updates.
• Add .dockerignore for best practice.

Commands to get SHA256 from docker:

curl -s 'https://hub.docker.com/v2/repositories/library/node/tags/20-alpine' | grep -o '"digest":"[^"]*"' | head -1 | cut -d'"' -f4

curl -s 'https://hub.docker.com/v2/repositories/library/python/tags/3.11-alpine' | grep -o '"digest":"[^"]*"' | head -1 | cut -d'"' -f4

Let me know if you want changes or if this is not something you want.