chore: create docker and singularity containers

[DelusionalSimon]

To ensure maximum reproducibility and easy integration into pipelines (like Nextflow or Snakemake), this task is to create a container for proChariot.

Tasks

• Create a Dockerfile in the project root.
• Implement a multi-stage build:
  • The build stage will use a full Python image to create a virtual environment and install prochariot (via pip install .).
  • The final stage will be a python:3.10-slim image and just copy the venv from the build stage.
• Set the ENTRYPOINT in the Dockerfile to ["prochariot"] so the container runs the tool by default (e.g., docker run prochariot_image --help).
• (Optional) Set up a GitHub Action to automatically build and publish the container to GitHub Container Registry (ghcr.io) or Docker Hub on new releases.
• (Optional) Submit the container to BioContainers so it's broadly available.