Merge pull request #25896 from raksonibs/fix/docs_step_6

Email deprecation for step 6 of tutorial

docs/getstarted/step_six.md

@@ -72,13 +72,14 @@ If you don't already have a terminal open, open one now:
 
     The format for the login command is:
 
-        docker login --username=yourhubusername --email=youremail@company.com
+        docker login 
 
     When prompted, enter your password and press enter. So, for example:
 
-        $ docker login --username=maryatdocker --email=mary@docker.com
-        Password:
-        WARNING: login credentials saved in C:\Users\sven\.docker\config.json
+        $ docker login
+        Login with your Docker ID to push and pull images from Docker Hub. If you don't have a Docker ID, head over to https://hub.docker.com to create one.
+        Username: 
+        Password:        
         Login Succeeded
 
 9. Type the `docker push` command to push your image to your new repository.