Document use of other Azure B2C user flows/policies

[bytesnz-doc]

Core Library

MSAL.js (@azure/msal-browser)

Wrapper Library

Not Applicable

Public or Confidential Client?

Public

Documentation Location

https://github.com/AzureAD/microsoft-authentication-library-for-js/blob/dev/lib/msal-browser/docs/working-with-b2c.md

Description

It would be good include how you should use msal-browser if you have mutliple Azure B2C user flows (e.g. separate user flows for sign up, sign in, password). You have to specify the user flow id (policy-id) in the authority URL, should it would be good to have a note on how to use other policies like if a user clicks the forget password link on a sign up user flow.

From the code, it looks like you can specify the authority URL in things like the redirectLogin() request parameters. Is this the best way to do it?