Add Docker container startup command to README.md

[cliffhall]

• In README.md
  • Add the command to start the Inspector UI in a Docker container
• In Dockerfile
  • use current-alpine3.22 as the base image

Motivation and Context

Instruction on how to launch in container is currently missing from the README. I was holding off to see if the container base image would be fixed, as 24-slim has a high vulnerability CVE which remains unfixed which allows running commands on the host as root. I chose the alpine image because all the slim variants have medium and low vulnerabilities. This image was the lowest vulnerability level running Node 24.

How Has This Been Tested?

This is testing the command added to the README with the current version in ghcr.io. We'll have to test the build with alpine after merge.

Breaking Changes

Nope.

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Documentation update

Checklist

• I have read the MCP Documentation
• My code follows the repository's style guidelines
• New and existing tests pass locally
• I have added appropriate error handling
• I have added or updated documentation as needed

Additional context