Public Contributor/Microsoft Employee setting

[guardrex]

One has to go to the @ext:docsmsft.docs-build extension settings to switch from Microsoft Employee to Public Contributor, but that's not called out anywhere. I recommend that you call that out to folks in VS's extension message about making the selection so that they know where to set the User Type to Public Contributor if they accidentally set it to MS employee, as I did by mistake.

[928PJY]

@shanluo911 we indeed display the message about how to change the user type when they select it right? let's add it into the readme as well. @guardrex thanks for the reporting.