set `publicSpreadsheetUrl` in `index.html` to set a sheet
expects the following columns, but easily updated:
* title
* author
* authorLast (used for sorting)
* isbn-10 (not displayed)
* isbn-13
* format
* genre
* publisher
* series
* volume
* year
* coverurl
* description
* notes
* signed (`yes` or blank)
## adding books using the google books API
1. update `SHEET_ID` and `SHEET_NAME` in `index.js`.
2. follow the instructions at <https://developers.google.com/sheets/api/quickstart/nodejs#step_1_turn_on_the_api_name>, and save the resulting json file to `.credentials/client_secret.json`.
the google books API is somewhat spotty; searching for a title at https://books.google.com/ will sometimes pull up a book and provide the ISBN they know it by. It also doesn't have comprehensive coverage of various editions of titles, and doesn't return image URLs or format information.
