Add mandatory code-review initial announcement & link to document index & code_reviews docs.

Change-Id: I8f8da9aa793b5818f2395795094f0e2313e0af25
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2321867
Commit-Queue: Andrew Whalley <[email protected]>
Auto-Submit: Yulan Lin <[email protected]>
Reviewed-by: Andrew Whalley <[email protected]>
Cr-Commit-Position: refs/heads/master@{#793687}
diff --git a/docs/README.md b/docs/README.md
index 2c89081..90753e4 100644
--- a/docs/README.md
+++ b/docs/README.md
@@ -110,6 +110,7 @@
 *   [Code Reviews](code_reviews.md) - Code review requirements and guidelines
 *   [Respectful Code Reviews](cr_respect.md) - A guide for code reviewers
 *   [Respectful Changes](cl_respect.md) - A guide for code authors
+*   [Mandatory Code-Review Rollout](code_review_owners.md) - Upcoming policy changes related to code review and OWNERS
 *   [LUCI Migration FAQ](luci_migration_faq.md) - FAQ on Buildbot-to-LUCI
     builder migration for Chromium
 *   [Tour of Continuous Integration UI](tour_of_luci_ui.md) - A tour of our