Have new members update their profile after signing up [Sign up wizard]

Currently, we just have these steps listed:
> 1. [Review the information on your profile](/me/edit) and make sure it is correct.
2. Make sure you get invited to our Flowdock organization (you'll need to talk to someone who has access)
3. Peruse the links we've provided below to learn about the organization and what tools we use
4. Help us with a project (We're a very project-oriented group, so we'd like to direct you to working on one)
- Look through the [projects we are currently working on](/projects) and see if you're interested in joining any of them
- Read [this document on how to contribute to a project](https://docs.google.com/document/d/1p3oehpGhFGLjorp6_T83BXdouPET62LqJFlOEJWEtq0)

Let's make it so users are prompted with the option to update their profile instead of forcing them to click on links.

Might want to reference designs in #148

Start at the sign-up wizard and review the existing onboarding steps, then reference the designs from issue #148. Add an optional prompt that lets new members update their profile after signing up instead of requiring them to follow the profile link. Done means the prompt appears in the wizard and the existing onboarding guidance remains available.

Written by the indexing model from the issue text.