docs: remove example usage from README (#77)

Author: busunkim96

README.rst

@@ -79,34 +79,11 @@ Windows
     <your-env>\Scripts\activate
     <your-env>\Scripts\pip.exe install google-cloud-dataproc
 
-Example Usage
-~~~~~~~~~~~~~
-
-.. code:: py
-
-    from google.cloud import dataproc_v1
-
-    client = dataproc_v1.ClusterControllerClient()
-
-    project_id = ''
-    region = ''
-
-
-    # Iterate over all results
-    for element in client.list_clusters(project_id, region):
-        # process element
-        pass
-
-    # Or iterate over results one page at a time
-    for page in client.list_clusters(project_id, region).pages:
-        for element in page:
-            # process element
-            pass
 
 Next Steps
 ~~~~~~~~~~
 
 -  Read the `Client Library Documentation`_ for Google Cloud Dataproc API
    API to see other available methods on the client.
 -  Read the `Product documentation`_ to learn more about the product and see
-   How-to Guides.
+   How-to Guides.