The short biography was "The Artist and the Mathematician: The Story of Nicolas Bourbaki, the Genius Mathematician Who Never Existed" [0]. It dedicates a good chunk of the book to the life of Grothendieck. Grothendieck was a member of the group that used the Nicolas Bourbaki pseudonym. It's a fun read you can finish in an afternoon. Not sure how accurate it is.
[0]: https://www.goodreads.com/book/show/208933.The_Artist_and_th...