(feat): Clarify signup page password input

[CaitlinCP]

Describe the feature

Currently, the signup page looks like this:

It would be nice to have the instructions on the page clarify that the two password bars are for password verification (ie: they must be the same value)

Requirements
Error handling is already present if the passwords aren't the same, so this would just be updating the html elements around the first and second password boxes to clarify that someone needs to enter their password, and then enter it again.