TODO-2 done, clean up of README too

README

@@ -31,8 +31,6 @@ python3 main.py
 MAYBE-1: when moving a book in a series (which is part of 2 series), do we pop-up offer to move parent/child series orders as well to match (think Thomas Covenant)
 
 #### TODOS:
-TODO-2:		delete sub_book from book:
-			- swap the 'add sub book' for 'remove from parent book' button and then act on it (separate route, simple sql exec and route back to (no-longer) child book) 
 TODO-3:		when remove a Parent book from a series:
 			- popup with: remove all sub books from series too?
 TODO-4: 	removing a subbook from a series
@@ -58,3 +56,4 @@ TODO-19:	icons on wish list, etc.?  (not sure I really want them, but if so)
 		 	- save: https://www.flaticon.com/free-icon/sold_463255?term=sold&page=1&position=6&related_item_id=463255
 TODO-20:	ORM all books load is slow
 			- should I lazy load all books (ajax the 2nd->last pages in, or not use ORM, and do a quick db.execute()....)
+TODO-21:	allow a way to add a book as a child of another existing book (opposite of rem_sub_book)