prepare release for resourcemanager (Azure#27868)

* prepare release for resourcemanager

* resolve comments

* resolve commetns

sdk/resourcemanager/Azure.ResourceManager/CHANGELOG.md

@@ -1,14 +1,23 @@
 # Release History
 
-## 1.0.0-beta.9 (Unreleased)
+## 1.0.0-beta.9 (2022-03-31)
 
 ### Features Added
 
-### Breaking Changes
+- New struct `ArmEnvironment`.
 
-### Bugs Fixed
+### Breaking Changes
 
-### Other Changes
+- Now all the resource classes would have a `Resource` suffix (if it previously does not have one).
+- Renamed some models to more comprehensive names.
+- Moved class `ManagementGroupResource` (previously `ManagementGroup`), `ManagementGroupCollection` and `ManagementGroupData` from `Azure.ResourceManager.Management` namespace to `Azure.ResourceManager.ManagementGroups`.
+- Moved class `ArmResource` and `ArmCollection` from `Azure.ResourceManager.Core` to `Azure.ResourceManager`.
+- Removed namespace `Azure.ResourceManager.Core` and `Azure.ResourceManager.Management`.
+- Removed class `ErrorDetail` and `ErrorAdditionalInfo`.
+- Removed `GetIfExists` methods from all the resource classes.
+- Changed `Scope` in `ArmClientOptions` to `ArmEnvironment`.
+- The constructor of `ArmClient` no longer accepts a `Uri` parameter, please use the `ArmEnvironment` in `ArmClientOptions` instead.
+- All properties of the type `object` were changed to `BinaryData`.
 
 ## 1.0.0-beta.8 (2022-01-29)
 

sdk/resourcemanager/Azure.ResourceManager/README.md

@@ -14,7 +14,7 @@ This package follows the [new Azure SDK guidelines](https://azure.github.io/azur
 Install the Azure Resources management library for .NET with [NuGet](https://www.nuget.org/):
 
 ```PowerShell
-Install-Package Azure.ResourceManager -Version 1.0.0-beta.8
+Install-Package Azure.ResourceManager -Version 1.0.0-beta.9
 ```
 
 ### Prerequisites