Pas évident qu'il faut faire défiler vers le bas lors de l'inscription

[vinothkannans (Vinoth Kannan)]

@awesomerobot

Instead of disabling it until the form is complete, we can allow people to click it, and then scroll them to the first incomplete input.

It’s done in the below open PR

UX: don't disable "create account" button & display error message for required fields.