Mention Virtual Cache support in the changelog (#370)

Author: wu-sheng

CHANGES.md

@@ -5,6 +5,8 @@ Release Notes.
 8.13.0
 ------------------
 
+**This release begins to adopt SkyWalking 9.3.0+ [Virtual Cache Analysis](https://skywalking.apache.org/docs/main/next/en/setup/service-agent/virtual-cache/).**
+
 * Support set-type in the agent or plugin configurations
 * Optimize ConfigInitializer to output warning messages when the config value is truncated.
 * Fix the default value of the Map field would merge rather than override by new values in the config.