Improve signup page

[kleenkanteen]

I'll add primevue as the component library: https://www.reddit.com/r/vuejs/comments/18ecyja/vue_ui_kitscomponent_libraries/. I'll edit the signup page to use it and look nice.

I'll also remove the info the user has to give wheng signing up so they just give their email and password. I'll delete the users table since supabase comes with its own auth.users table.