Make Sign up look like UX sketches

[joshi1983]

This work is likely to involve:

• adjusting content in hhaccessibility.github.io\app\resources\assets\sass\app.scss
• running gulp to generate the css
• and adjusting mostly HTML content in hhaccessibility.github.io\app\resources\views\pages\signup.blade.php

Don't worry if the form works. Another issue will cover that.

[joshi1983]

The sign up page looks a lot like the mockup now so closing this issue.

[joshi1983]

If a user is already signed in, should the signup page look or say anything different? Should it say in strong or bold text, "You already have an account and are signed in."?

After signing in, only the profile page looks different from not being signed in. I wonder if that lack of clarity about whether they're signed in could confuse people into trying to sign up multiple times.