chore: add basic usage example for APIBasedAuth

[swain]

Motivation

Another team wants to use this! These are basic docs, will plan to improve them later.

[loscm]

Requested review from a random @lifeomic/security team member, @bishopb, due to term: auth.

This review is not blocking and is for broader awareness. Consider if this change requires deeper security review and ask when it is necessary.

• Automation | #pr-flagged-sec-review