update CHANGELOG.md for v0.2.1
## 0.2.1
FEATURES:
+
+* **New Resource** `azuredevops_project_pipeline_settings` [#556](https://github.com/microsoft/terraform-provider-azuredevops/issues/556)
+
BUG FIX:
+* `azuredevops_group` - Fix scope not set [#542](https://github.com/microsoft/terraform-provider-azuredevops/issues/542)
+* `azuredevops_branch_policy_build_validation` - Fix `file_pattern` disordered. [#539](https://github.com/microsoft/terraform-provider-azuredevops/issues/539)
+* `azuredevops_variable_group` - Fix create 401 authorization error. [#541](https://github.com/microsoft/terraform-provider-azuredevops/issues/541)
+* `azuredevops_group` - Can not create group at project level. [#558](https://github.com/microsoft/terraform-provider-azuredevops/issues/558)
+* `azuredevops_project` - Unable disable/enable project feature artifacts. [#568](https://github.com/microsoft/terraform-provider-azuredevops/issues/568)
+
IMPROVEMENTS:
-BREAKING CHANGE:
+* Update document - [#543](https://github.com/microsoft/terraform-provider-azuredevops/issues/543)
+* Deprecate `azuredevops_serviceendpoint_azuredevops`, use `azuredevops_serviceendpoint_runpipeline` instead - [#565](https://github.com/microsoft/terraform-provider-azuredevops/issues/565)
## 0.2.0
