Feature: start reading where last left off

[marisademeglio]

Check a stored value on startup to see if we should load a different page. Create a prompt for the user and give them the option to go to that page.

This may also force me to sort out per-publication preferences :)

[marisademeglio]

Also mentioned by a user who gave this feedback Oct 2022

"synchronizations when I close a book by mistake and re-open it, the book opens from the beginning. Can we save user preference and his last position using cookies?"