GitLab

This CL adds documentation for the feedback API as well as the
declarativeNetRequestFeedback permission.

The getMatchedRules has also been made available for beta.

Bug: 1044702
Change-Id: I9752110fce82b56efe5666fc811c018b1cf2e895
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2032415Reviewed-by: Karan Bhatia <karandeepb@chromium.org>
Commit-Queue: Kelvin Jiang <kelvinjiang@chromium.org>
Cr-Commit-Position: refs/heads/master@{#737853}