Add community prebuilt Docker image reference and note on local LLM support

[855princekumar]

Summary

Adds a reference to a community-maintained prebuilt Docker image to simplify OpenMAIC deployment without requiring a local build.

Related Issues

N/A

Changes

• Added optional prebuilt Docker image usage under Docker section
• Included docker run and compose examples
• Linked external deployment guide
• Added note on potential local LLM support

Type of Change

• Bug fix (non-breaking change that fixes an issue)
• New feature (non-breaking change that adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Documentation update
• Refactoring (no functional changes)
• CI/CD or build changes

Verification

Steps to reproduce / test

1. Follow existing Docker setup
2. Run using provided prebuilt image command
3. Verify application loads on localhost

What you personally verified

• Verified container runs successfully using prebuilt image
• Confirmed application loads and responds correctly
• Ensured no changes to existing setup flow

Evidence

• CI passes (pnpm check && pnpm lint && npx tsc --noEmit)
• Manually tested locally
• Screenshots / recordings attached (if UI changes)

Checklist

• My code follows the project's coding style
• I have performed a self-review of my code
• I have added/updated documentation as needed
• My changes do not introduce new warnings