docs: Fix to nav, added _book.yaml am: 584c09929e
am: 6856d6f0b7

* commit '6856d6f0b76527c75c5147c392f1bb10d5f121fb':
  docs: Fix to nav, added _book.yaml

Change-Id: Ib3843b9ab63076cac75aea6517027de634a361a8