Add note to localizers

Author: Tim Bannister

content/en/docs/concepts/security/cloud-native-security.md

@@ -19,6 +19,11 @@ help you deploy a secure cloud native platform.
 
 ## Cloud native information security
 
+{{< comment >}}
+There are localized versions available of this whitepaper; if you can link to one of those
+when localizing, that's even better.
+{{< /comment >}}
+
 The CNCF [white paper](https://github.com/cncf/tag-security/tree/main/security-whitepaper)
 on cloud native security defines security controls and practices that are
 appropriate to different _lifecycle phases_.