Update authenticating.html.md.erb

[x64bytes]

The existing uaac output of client info is wrong, There is no --override option when creating a client. Also, Providing the uaa command helps as there are typos in the manner uaa grant types listed in the existing document versus the actual output.

The proposed changes are validated and followed from the general Github link

https://github.com/pivotalservices/concourse-pipeline-samples/tree/master/concourse-pipeline-patterns/uaa-authentication

[cf-gitbot]

We have created an issue in Pivotal Tracker to manage this. Unfortunately, the Pivotal Tracker project is private so you may be unable to view the contents of the story.

The labels on this github issue will be updated when the story is started.

[cf-meganmoore]

thanks, @in4sometech !