You can find it here:
From the Details:
This download is an Adobe® PDF of the entire contents of the Windows Server 2012 R2 and Windows Server 2012 section of the Microsoft TechNet Library, for the convenience of Windows Server users who have limited Internet access, or require a portable version of the Windows Server 2012 R2 and Windows Server 2012 documentation. The PDF is 116 MB, and 7,970 pages in length.
That's right folks that is almost 8,000 pages. This is not something you are going to read cover to cover quickly but it is a great reference and ctrl+F always works. I really like that the document also points you to other great sources like the askds blog. The next version will have askpfe entries as they are taking over much of the on-prem blogging these days. There is a lot of Active Directory content but there is a lot more in this document.
I also posted this to reddit/sysadmin a few days ago and it received a good response. One of the comments said that we also need a similar PDF for exchange.
There are not many companies that document and provide anything this thorough so a huge thanks to all the Microsoft teams that have worked to make this happen. Anyone that has been involved in writing documents or tech writing knows that this takes a lot of time and effort.