Add support for importing data from TheStoryGraph

[aethior]

Rel: #9

TheStoryGraph was created as an alternative to GoodReads.

This app allows you to download a CSV file containing your information, so it would be a good idea to add this as an import option.

If necessary, I could provide a CSV file containing my library for testing.

[Mozzo1000]

Great suggestion! This will not be hard at all as long as StoryGraph have ISBNs included in the export. We just have to map their structure to ours.

[aethior]

Example of the export format:

Trabajo, consumismo y nuevos pobres,Zygmunt Bauman,Victoria de los �ngeles Boschiroli   (Translator),9788474327502,paperback,to-read,2022/11/26,"","",0,"",,,,,,,,,"",,"",Yes

[Mozzo1000]

StoryGraph export file format

"Your export will contain the following information: book title, book authors and contributors, ISBN, edition format, read status, your review and rating, date added to library, read dates, read count, whether the edition is owned, and any custom tags."

File format: CSV
Delimiter: comma ,
Example file: 2d23d820cedbfe3229b1e2becb16928b3861673f8998426622299a33a6f04863.csv

Header columns of CSV

Field	Compatible (Yes/No)	Format	Options	Comment
Title	Yes	TEXT
Authors	Yes	TEXT	Single or multiple authors, separated by a comma ,
Contributors	No
ISBN/UID	Yes	TEXT	Empty, ISBN or UID	We can import only if the row has a valid ISBN
Format	No
Read Status	Yes	TEXT	did-not-finish, read, currently reading, to-read
Date Added	Yes	DATE	YYYY-MM-DD (2026-05-25)
Last Date Read	Yes	DATE	YYYY-MM-DD (2026-05-25) or Empty
Dates Read	Yes	DATE	YYYY/MM/DD-YYYY/MM/DD (2026/05/21-2026/05/25, 2026/01/01-2024/01/02)	Multiple read dates are separated by a comma ,. Without an end date it will just be YYYY/MM/DD- (2026/05/25-). Without a start date it will only display the end date as YYYY-MM-DD (2026-05-25)
Read Count	No
Moods	No
Pace	No
Character- or Plot-Driven?	No
Strong Character Development?	No
Loveable Characters?	No
Diverse Characters?	No
Flawed Characters?	No
Star Rating	Yes	FLOAT	0-5	Increments by .25 (1.25, 1.50, 1.75 etc)
Review	No
Content Warnings	No
Content Warning Description	No
Tags	No
Owned?	No