Support multi-factor auth for publishing

[zachbryant]

Hello 👋 Npm currently supports MFA for publishing, but beachball errors out. It would be awesome if beachball publish would prompt me for my OTP. Currently I can either downgrade publish security or use npm publish on it's own, but I can't publish with MFA through beachball.

[danhaller]

One other thing you can do is use npm's environment variables:

NPM_CONFIG_OTP=<your otp> npx beachball publish