title: How to get logged in user info in Office app code
body: <p>I need help in How to get logged in user in office app code. It's a office JSOM (JavaScript Object Model) Api that we use to get information from MS Office product like to read content of MS Word document in which I am using my app to save this content into somewhere for example in SharePoint Document Library as a word document file. 
  So I need to know the current user's information like logged in id etc so I can identify who saved this document into SharePoint.
  Any pointers will be helpful.</p>