Fix docs on task-driver-sk.
Fix docs on task-driver-sk.

Change-Id: Id334573724433a695623370895e52898cb037a7e
Reviewed-on: https://skia-review.googlesource.com/c/buildbot/+/222880
Reviewed-by: Eric Boren <0e499112533c8544f0505ea0d08394fb5ad7d8fa@google.com>
Commit-Queue: Joe Gregorio <b9cf2471ff6d33504cafe8e6f356b732b2cadced@google.com>

google/skia-buildbot,google/skia-buildbot,google/skia-buildbot,google/skia-buildbot,google/skia-buildbot,google/skia-buildbot,google/skia-buildbot,google/skia-buildbot