title: Embed Devise new session form in other controllers' pages
body: <p>My Rails 5.2, Devise 4.7 app has the standard single sign_in page  for new devise sessions.</p>
  
  <p>I want the user to be able to browse a few different pages before signing in, and for each page to have the sign in form on it.</p>
  
  <p>How can I display the devise form for new sessions in the views of other controller actions? Is there a way to run the code from the <code>Devise::SessionsController#new</code> action, from my other controllers? Or do I need to keep a single signin page for new sessions and then add custom things to the page via separate ajax actions?</p>