Add multi-factor authentication example to documentation

[jandix]

Currently, I am setting up a feathers.js app with the local authentication strategy. I would like to add SMS as a second factor for every login. Unfortunately, I can’t find any example adding multiple-factors to local authentication strategies. Are there any resources on how to include a second factor using the local strategy and if so can they be added to the official documentation? I think that would help a lot of people to secure their applications.

[jandix]

This issue is linked to #1601 and can be closed.