update bookmaker

change https://skia-review.googlesource.com/c/skia/+/91380
should have triggered a bookmaker failure but, while
it reported the error it did not return that the check
failed. See
https://chromium-swarm.appspot.com/task?id=3adfe04df6f9ce10&refresh=10

Update bookmaker to detect and return error

also, add some SkImage examples
fixed some linefeeds

TBR=bsalomon@google.com
Docs-Preview: https://skia.org/?cl=90883
Bug: skia:6898
Change-Id: I3530c8d81785b71568f6229c2aad3259dded59d7
Reviewed-on: https://skia-review.googlesource.com/90883
Commit-Queue: Cary Clark <caryclark@skia.org>
Reviewed-by: Cary Clark <caryclark@skia.org>
7 files changed