This documentation can be read any way you want. If there are specific sections you are interested in, read those. If you have never set a kernel variable in linux before in your life, read the first chapter after this and then read the sections you feel intrigued by. If you feel like reading it from top to bottom, do that. If you feel like reading it backwards to find hidden messages, do that. If you feel like reading in encrypted format, well, nothing is stopping you.
What I am trying to say is the following, read the sections that you want to read and that you think would be informative to you, and if there is something you do not understand, read the corresponding bits either here or in some other document. I will not tell you how to read this document since everyone will probably have bits and pieces they already know how they work.