== Background
Currently, when a user selects to download a page in two-column format, they are redirected to a "rendering finished" page which has a button for downloading the PDF (https://en.wikipedia.org/w/index.php?title=Special:Book&bookcmd=rendering&return_to=Main+Page&collection_id=f76862132045e12d1f62c3c065c54af7f3f8b2b7&writer=rdf2latex&is_cached=1)
For the electron option, we currently have no such page and selecting "download as PDF" automatically generated the PDF
We would like to investigate whether it's worth it to have a similar page for the updated PDF renderer. In the future, this page may also contain setting and customization for the PDF.
== Acceptance criteria
Redesign download as pdf page to account for:
[] Rendering updates (currently done by percentage)
[] Rendering completion and download button
[] Page must contain size (if available)
[] Page must contain article name
[] Remove old page (selections screen)
[] Update instrumentation
[] Feature flag and add to beta cluster
== Prototype
https://wikimedia.invisionapp.com/share/MSD8GDQBH#/screens/250732064