AO3 Progress Bookmark

Features:
- bookmark at the page scroll position. (allowing users to bookmark up to 1000 AO3 works)
- backup page content in case of AO3 service down
- optional UI enhancements

This extension is not meant to replace the AO3 bookmark feature. Instead, it serves as a temporary place for readers to keep track of their reading progress. (Think of it as a way to manage the numerous AO3 tabs you had opened, which you would want return to where you left off at a later time).

For permanent saving of an AO3 work for future reference, I recommend using AO3's built-in bookmark feature.