If you go to the linked URL (https://beletronics.wordpress.com/learn-basic-electronics), and then click "Learn basic electronics – click to read", the table of contents shows "The building blocks" as step 1. The complete contents of this section are:

  The building blocks  
  Simplicity is the ultimate sophistication.  
  (Leonardo da Vinci)

The absolute next paragraph is the one I quoted. I'm not sure what other hidden introductory chapter you're referring to.