Add docs for how the various flows work: cli vs browser flow, and overview of all tokens/creds with lifetimes

[cfryanr]

Is your feature request related to a problem? Please describe.

This would document the answer to very commonly asked questions.

Describe the solution you'd like

A new doc page on the public web site.

Describe alternatives you've considered

None.

Are you considering submitting a PR for this feature?

Yes. Docs only, so no tests or architectural changes required.

• How will this project improvement be tested?
• How does this change the current architecture?
• How will this change be backwards compatible?
• How will this feature be documented?

Additional context

E.g. this question https://kubernetes.slack.com/archives/C01BW364RJA/p1673968325113179