Update changelog (Azure#34710)

Author: vishweshbankwar

sdk/monitor/Azure.Monitor.OpenTelemetry/CHANGELOG.md

@@ -1,11 +1,7 @@
 # Release History
 
-## 1.0.0-beta.1 (Unreleased)
+## 1.0.0-beta.1 (2023-03-07)
 
-### Features Added
+* Initial release of `Azure.Monitor.OpenTelemetry`.
 
-### Breaking Changes
-
-### Bugs Fixed
-
-### Other Changes
+This is a beta version, so breaking changes are possible in subsequent releases as we improve the product. To provide feedback, please submit an issue in our [Azure SDK for .NET GitHub repo](https://github.com/Azure/azure-sdk-for-net/issues).