+ docker interactive instructions

[sgoley]

Add Docker deployment instructions

• Added Docker configuration section to README.md showing users how to run the FRED MCP
• Server via Docker container with proper environment variable setup for the FRED API key.
• Prevents Docker container from immediately exiting on launch via -i interactive flag

Closes #10

[stefanoamorelli]

Looks good @sgoley thanks a lot!

Do you mind signing the commit with GPG signature and amending to this PR so that we can merge to main?

You can read more about GPG signature on Github here: https://docs.github.com/en/authentication/managing-commit-signature-verification/signing-commits

And once that's setup you can git commit --amend --no-edit -S and git push --force to push to this same branch without adding a new commit.

[stefanoamorelli]

Thanks a lot!