index: add race detector doc link

Change-Id: I3e8d2bfd83250e99a2bc0e80e871a8ace6ba6634
Reviewed-on: https://go-review.googlesource.com/c/wiki/+/558555
Commit-Queue: Hyang-Ah Hana Kim <hyangah@gmail.com>
Auto-Submit: Hyang-Ah Hana Kim <hyangah@gmail.com>
Reviewed-by: Hyang-Ah Hana Kim <hyangah@gmail.com>
diff --git a/index.md b/index.md
index 643b1c2..6a30454 100644
--- a/index.md
+++ b/index.md
@@ -149,6 +149,7 @@
   - [Timeouts](Timeouts) - Abandon async calls that take too long
   - [LockOSThread](LockOSThread)
   - [MutexOrChannel](MutexOrChannel) - When to use one vs the other
+  - [RaceDetector](https://go.dev/doc/articles/race_detector) - How to detect and fix race conditions
 - Working with Databases
   - [database/sql](http://go-database-sql.org/) - Online tutorial for working with the database/sql package.
   - [SQLDrivers](SQLDrivers)