[Personalizer] Update change log for 2.0.0-beta.2 of Personalizer (Az…

…ure#27341)

* Update change log for 2.0.0-beta.2 of Personalizer

* Make code types stand out

sdk/personalizer/Azure.AI.Personalizer/CHANGELOG.md

@@ -1,14 +1,15 @@
 # Release History
 
-## 2.0.0-beta.2 (Unreleased)
+## 2.0.0-beta.2 (2022-03-08)
 
 ### Features Added
+- Provide customers with much lower latency and more transactions per second than the current service limits.
+- Provide subsampling for customers so that only subsampled data are processed.
+- Provide a model import API to allow customers to warm start the Personalizer service.
 
 ### Breaking Changes
-
-### Bugs Fixed
-
-### Other Changes
+- In `PersonalizerAdministrationClient`, `GetPersonalizerModel` and `GetPersonalizerModelAsync` are replaced with `ExportPersonalizerModel` and `ExportPersonalizerModelAsync`.
+- In `PersonalizerClientOptions`, `ServiceVersion` is changed from V1_1_preview_1 to V1_1_preview_3.
 
 ## 2.0.0-beta.1 (2021-10-05)