Update GCP auth readme (#470)

## Changes
<!-- Summary of your changes that are easy to understand -->
- The azure doc link was misplaced. Moving it up under the azure auth
section

## Tests
<!-- 
How is this tested? Please see the checklist below and also describe any
other relevant tests
-->

- [ ] `make test` run locally
- [ ] `make fmt` applied
- [ ] relevant integration tests applied

Author: edwardfeng-db

README.md

@@ -174,6 +174,8 @@ w = WorkspaceClient(host=input('Databricks Workspace URL: '),
                     azure_client_secret=input('AAD Client Secret: '))
 ```
 
+Please see more examples in [this document](./docs/azure-ad.md).
+
 ### Google Cloud Platform native authentication
 
 By default, the Databricks SDK for Python first tries GCP credentials authentication (`auth_type='google-credentials'`, argument). If the SDK is unsuccessful, it then tries Google Cloud Platform (GCP) ID authentication (`auth_type='google-id'`, argument).
@@ -199,8 +201,6 @@ w = WorkspaceClient(host=input('Databricks Workspace URL: '),
 
 ```
 
-Please see more examples in [this document](./docs/azure-ad.md).
-
 ### Overriding `.databrickscfg`
 
 For [Databricks native authentication](#databricks-native-authentication), you can override the default behavior for using `.databrickscfg` as follows: