Scripting the port numbers in help, adding password reminder

The "Encryption instructions" in the landing page help is now scripted to display commands using the given port from "Connection settings" just like hostname is used in the cert generation command.

I also added a reminder about setting a password in the Encryption instructions. It's easy to forget when following a step-by-step instruction.

These changes only affect the help text on the landing page, and should be quite uncontroversial.