8.7.0 changelog (#3184)

* 8.7.0 changelog

* Update CHANGELOG for version 8.7.0

* Update CHANGELOG.md

Author: pmaytak

CHANGELOG.md

@@ -1,5 +1,13 @@
 See the [releases](https://github.com/AzureAD/azure-activedirectory-identitymodel-extensions-for-dotnet/releases) for details on bug fixes and added features.
 
+8.7.0
+=====
+## Bug Fixes
+- Add back internal methods `IsRecoverableException` and `IsRecoverableExceptionType` whose signatures were changed in the previous version. See [#3181](https://github.com/AzureAD/azure-activedirectory-identitymodel-extensions-for-dotnet/issues/3181).
+
+## New Features
+- Make `Cnf` class public and move it to Microsoft.IdentityModel.Tokens package. See [#3165](https://github.com/AzureAD/azure-activedirectory-identitymodel-extensions-for-dotnet/issues/3165).
+  
 8.6.1
 =====
 ## Bug fix