Update URL slug to avoid using subdomains

[glenn-sorrentino]

Is your feature request related to a problem? Please describe. The URL for the product right now is tips.hushline.app, making DNS logs show that the user was on the app, rather than the public informational website, decreasing privacy for the whistleblower's internet activity.

Describe the solution you'd like Update the URL to this pattern: hushline.app/tips. The directory would be hushline.app/tips/directory. A message submission page is hushline.app/tips/submit_message/scidsg