add test plan

Author: Han Kang

keps/sig-instrumentation/3466-kubernetes-component-health-slis/README.md

@@ -232,7 +232,7 @@ when drafting this test plan.
 [testing-guidelines]: https://git.k8s.io/community/contributors/devel/sig-testing/testing.md
 -->
 
-[ ] I/we understand the owners of the involved components may require updates to
+[ X ] I/we understand the owners of the involved components may require updates to
 existing tests to make this code solid enough prior to committing the changes necessary
 to implement this enhancement.