Add a Docker quickstart

[kmadan]

Goal

Ship a Dockerfile and a documented one-line container run that produces a generated report. Goal: a reviewer with no Python installed can see what AICertify produces in under two minutes.

Why this matters

Many enterprise reviewers (legal, compliance, security) cannot install Python directly. A Docker path lowers the barrier from 'install Python + poetry' to 'docker run'.

Files likely involved

• New: Dockerfile at repo root (or under docker/)
• New: docs/integrations/docker.md
• Possibly: a docker-compose.yml if multi-container makes sense

Acceptance criteria

• docker build -t aicertify . produces a working image under 1 GB
• docker run --rm aicertify runs the quickstart and prints the path of the generated report
• docker run -v /home/kapil/Projects/AICertify/contracts:/contracts aicertify ... accepts user contracts
• README links to the Docker path under Quick Start
• Multi-stage build to keep the runtime image small

Help

Comment here if you want to work on this and I will help you get started. First-time contributors are welcome — open a draft PR early and I'll review.