I would read That rule as assuming you already have a US visa in your passport at time of entry not that you are just applying for one.
By the time you make an appointment for the visa interview you might not even have a month left so the chances of a visa officer issuing a visa seem slim. Guess you can always try though given nobody here is a US visa officer.
As for documents check the official US visa site.
https://ca.usembassy.gov/visas/