This CL combines the two contributing files from the merge into a single
file in CONTRIBUTING.md.
BUG=dawn:1356
Change-Id: I863f008f2f842222900b312ce9cc6382d82a32ce
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/86206
Auto-Submit: Dan Sinclair <dsinclair@chromium.org>
Reviewed-by: Corentin Wallez <cwallez@chromium.org>
Commit-Queue: Corentin Wallez <cwallez@chromium.org>