Trusted Publisher documentation

[jasonkarns]

Description: Document an example of how publishing to npm is handled if using npm's Trusted Publisher setup. In particular, explicitly answer the question whether NODE_AUTH_TOKEN needs to be set at all if using Trusted Publisher. (Presumably no?)

Justification: Npm is pushing folks towards Trusted Publisher setup and away from token auth. This action should acknowledge that reality and document an example of what is necessary (or not necessary!) when using Trusted Publisher. Presently, there isn't so much as a mention of Trusted Publisher setup or configuration impact.

Are you willing to submit a PR?