[digital-twins-core] Update date in changelog (#12002)

sdk/digitaltwins/digital-twins-core/CHANGELOG.md

@@ -1,6 +1,11 @@
 # Release History
 
-## 1.0.0-preview.2 (Unreleased)
+## 1.0.0-preview.2 (2020-10-23)
+
+- This release is an update of the preview with the following changes
+  - Package name changed to: `@azure/digital-twins-core`.
+  - Add span to all APIs
+- Pull request containing the changes: https://github.com/Azure/azure-sdk-for-js/pull/11872
 
 ## 1.0.0-preview.1 (2020-09-03)
 
@@ -8,4 +13,4 @@
   idiomatic to the JavaScript ecosystem. The reasons for most of the changes in this update can be found in the
   [Azure SDK Design Guidelines for TypeScript](https://azure.github.io/azure-sdk/typescript_introduction.html).
 - Initial release:
-  - Package name `@azure/digital-twins-core`.
+  - Package name `@azure/digital-twins`.