Add dockerfile

[danvergara]

Changes

• Remove the localhost from the ListenAndServe function
• Add a Dockerfile to build the container image
• Add a .dockerignore file
• Add target commands to the Makefile to run and build the container image

I'm using debian:bookworm-slim as a final stage image just in case we need external dependencies available for Debian-like systems.

Image built on my machine (GOOS=linux and GOARCH=amd64) is just 86.4 MB size. I can be smaller if I manage to avoid to use external dependencies.