Digest UX Improvements

[ethanresnick]

• When the subscribe succeeds, rather than directing the user to a new page, the original form/text on the homepage could disappear and just be replaced with the success message?
  • would cause problems if people want to sign up two different email addressses—or, far more likely—if they mistype their email. so maybe the original form would come back on reload?
• Also, it might be nice to design a system for collecting secondary information. For example, we might want to optionally have the person create an api account and fill out a profile. We could do this by having these fields appear, e.g., on the page the user lands on when they click the link to confirm their email.