Add description
Add dependent gems
Add epub-search init command
Make configuable by file
Make init accept databse directory
Remove unnecessary comment
Change table name: Books -> Pages
Add add command
Add search command
SEARCH_WORD -> WORD
Define config file fallback chain
Fix desc and option of init command
Add .exit_on_failure? to exit with status 1 when failure
Add remove command
Output only lines including search word when searching