Add link to text proto

Change-Id: Ic9e38eda3c0c9db4288b1f19dda0561a91a7d57b
Reviewed-on: https://skia-review.googlesource.com/c/buildbot/+/703779
Auto-Submit: Kevin Lubick <kjlubick@google.com>
Commit-Queue: Ravi Mistry <rmistry@google.com>
Reviewed-by: Ravi Mistry <rmistry@google.com>
diff --git a/autoroll/README.md b/autoroll/README.md
index afeecb0..fb25047 100644
--- a/autoroll/README.md
+++ b/autoroll/README.md
@@ -54,6 +54,8 @@
 [file a bug](https://bugs.chromium.org/p/skia/issues/entry?template=Autoroller+Bug)
 to request a change.
 
+The text proto which governs configuration can be read [here](https://skia.googlesource.com/buildbot/+/refs/heads/main/autoroll/go/config/config.proto).
+
 ## AutoRoll Modes
 
 There are three modes in which the roller may run: