Spacedbooks

This is a command line tool that provides convenient way to manage "spaced repetition" of books to faciliate
effective long-term learning.

Workflow:

1. You've read new book 3 days ago.

2. Add this book into db: spacedbooks add-book "The Shallows" "Nicholas Carr" --isbn=978-0393357820 -0.

3. Check intervals in config and set them to your prefered spaced repetition schedule. Since most spaced
   repetition research is limited to short-term retrieval, I've found only single truly relevant research
   paper and adopted its recommendations in the default config intervals.
   (Spacing effects in learning: A temporal ridgeline of optimal retention - https://escholarship.org/uc/item/0kp5q19x).

4. Use spacedbooks.py without arguments to generate list of books that should be reviewed or use
   cron, launchd etc. to run spacedbooks.py send-mail periodically to receive notifications by email.

   ===================
   ‖ BOOKS TO REVIEW ‖
   ===================
   [4] "The Coddling of the American Mind: How Good Intent..." by Jonathan Haidt
   [3] "Digital Minimalism: Choosing a Focused Life in a N..." by Cal Newport
   [2] "Understanding How We Learn: A Visual Guide" by Yana Weinstein, Megan Sumeracki
   [1] "The Warship" by Neal Asher
   [5] "The Shallows" by Nicholas Carr
   

5. Run spacedbooks.py add-review ... to log that you have reviewed the book.