Clean up contributing documentation post tint merge

Tint's contributing documentation end up in the top-level
CONTRIBUTING.md, but should live in its project specific
documentation.

BUG=dawn:1356

Change-Id: I64d8a10d11e11922756c9d7bb02678f4bf92442b
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/86100
Commit-Queue: Ryan Harrison <rharrison@chromium.org>
Auto-Submit: Ryan Harrison <rharrison@chromium.org>
Kokoro-Run: Ryan Harrison <rharrison@chromium.org>
Reviewed-by: Dan Sinclair <dsinclair@chromium.org>
Commit-Queue: Dan Sinclair <dsinclair@chromium.org>
Reviewed-by: Austin Eng <enga@chromium.org>
diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index 329011e..fe8a3aa 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -1,45 +1,5 @@
-# How to Contribute
+See docs/dawn/contributing.md for instructions about how to contribute
+to Dawn portion of the codebase.
 
-We'd love to accept your patches and contributions to this project. There are
-just a few small guidelines you need to follow.
-
-## Contributor License Agreement
-
-Contributions to this project must be accompanied by a Contributor License
-Agreement. You (or your employer) retain the copyright to your contribution;
-this simply gives us permission to use and redistribute your contributions as
-part of the project. Head over to <https://cla.developers.google.com/> to see
-your current agreements on file or to sign a new one.
-
-You generally only need to submit a CLA once, so if you've already submitted one
-(even if it was for a different project), you probably don't need to do it
-again.
-
-## Code reviews
-
-All submissions, including submissions by project members, require review. We
-use [Dawn's Gerrit](https://dawn-review.googlesource.com/) for this purpose.
-
-Submissions should follow the [Tint style guide](docs/tint/style_guide.md).
-
-## Pushing to Gerrit
-
-Each change requires a `Change-Id` field in the commit message, which is generated by the [Gerrit commit-msg hook](](https://gerrit-review.googlesource.com/Documentation/cmd-hook-commit-msg.html)). \
-In a bash terminal, with the current path set to your tint source tree, this can be obtained by running the following:
-
-```bash
-f=`git rev-parse --git-dir`/hooks/commit-msg ; mkdir -p $(dirname $f) ; curl -Lo $f https://gerrit-review.googlesource.com/tools/hooks/commit-msg ; chmod +x $f
-```
-
-If you've already locally committed a change without the `Change-Id`, running `git commit --amend` will add the missing `Change-Id`.
-
-To create a Gerrit change for review, type:
-
-```bash
-git push origin HEAD:refs/for/main
-```
-
-## Community Guidelines
-
-This project follows
-[Google's Open Source Community Guidelines](https://opensource.google.com/conduct/).
+See docs/tint/contributing.md for instructions about how to contribute
+to Tint portion of the codebase.
diff --git a/docs/tint/contributing.md b/docs/tint/contributing.md
new file mode 100644
index 0000000..329011e
--- /dev/null
+++ b/docs/tint/contributing.md
@@ -0,0 +1,45 @@
+# How to Contribute
+
+We'd love to accept your patches and contributions to this project. There are
+just a few small guidelines you need to follow.
+
+## Contributor License Agreement
+
+Contributions to this project must be accompanied by a Contributor License
+Agreement. You (or your employer) retain the copyright to your contribution;
+this simply gives us permission to use and redistribute your contributions as
+part of the project. Head over to <https://cla.developers.google.com/> to see
+your current agreements on file or to sign a new one.
+
+You generally only need to submit a CLA once, so if you've already submitted one
+(even if it was for a different project), you probably don't need to do it
+again.
+
+## Code reviews
+
+All submissions, including submissions by project members, require review. We
+use [Dawn's Gerrit](https://dawn-review.googlesource.com/) for this purpose.
+
+Submissions should follow the [Tint style guide](docs/tint/style_guide.md).
+
+## Pushing to Gerrit
+
+Each change requires a `Change-Id` field in the commit message, which is generated by the [Gerrit commit-msg hook](](https://gerrit-review.googlesource.com/Documentation/cmd-hook-commit-msg.html)). \
+In a bash terminal, with the current path set to your tint source tree, this can be obtained by running the following:
+
+```bash
+f=`git rev-parse --git-dir`/hooks/commit-msg ; mkdir -p $(dirname $f) ; curl -Lo $f https://gerrit-review.googlesource.com/tools/hooks/commit-msg ; chmod +x $f
+```
+
+If you've already locally committed a change without the `Change-Id`, running `git commit --amend` will add the missing `Change-Id`.
+
+To create a Gerrit change for review, type:
+
+```bash
+git push origin HEAD:refs/for/main
+```
+
+## Community Guidelines
+
+This project follows
+[Google's Open Source Community Guidelines](https://opensource.google.com/conduct/).