My guess is that it was removed because it is redundant. You can find all its content under "keywords" in the 4th line of documentation and the Types downwards that page.
I disagree. Documentation on keywords, and more importantly the views, are needed in printable format. On-line documentation is difficult and time consuming to use. There was a file called "KeyWords_Views.pdf" and the title page says "Keywords Views Collections". I would like to know where it is available. It should have never been removed from "Beginners Guide.pdf" where it belongs.