Add console command to disable 2FA enforce

What does this MR do?

Updates documentation to expose how 2FA enforce can be changed using rails command.

Related issues

Not an issue as such, but during performing some testing on my instance for a customer. I ran into the issue of enforcing 2FA on my instance by mistake. I could not turn it off until I found out this setting. The only other way was to configure 2FA for an admin user, and turn it of from the UI. This command was the easiest.

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