Fix arrangement of arguments.

[conniey]

What does this PR do?

Fixes instruction for using env file in docker.

GitHub issue number?

Fixes #308

Checklist before merging

• I have read the contribution guidelines on pull request process, code style, and testing.
• Title of the pull request is clear and informative.
• There are a small number of commits, each of which have an informative message. This means that previously merged commits do not appear in the history of the PR. For more information on cleaning up the commits in your PR, see this page.
• If it's a core feature, I have added thorough tests.
• If it's a noteworthy bug fix or new feature, I have added an entry in CHANGELOG.md with a link back to the PR or issue
• Have a team member run live tests:
  • Team Member: Inspect PR for security issues before queueing a test run
  • Team Member: Add this comment to the pr /azp run azure - mcp to start the run

[joshfree]

Should this live in a sample or someplace other than only the readme.md too?

[conniey]

Should this live in a sample or someplace other than only the readme.md too?

No. This is what users have to copy and paste into their mcp.json to get it to work, similar to the manual install instructions for using npx.