anchor.diff:  ====
   Why do you need to configure the files to be rendered?
   
  -Asciidoctor renders all `.adoc` files by default, no matter if these are the main documents or just chapters you want to include.
  -In addition, it is quite likely that you only want to convert a few files to PDF.
  -Hence, you have to configure which ones.
  +Asciidoctor renders all `.adoc` files by default. It doesn't matter if they are the main documents or chapters you want to include.
  +Most people only want to convert selected files to PDF, so that's why you need to configure which ones.
  +
   ====
   
   == Creating a Custom PDF Theme
  
positive.code: ]
  ```
  
  Add the files which you want to be rendered along with the format. 
  In this case `pdf`.
  
  .Hint
  
negative.code: The result looks more like a nicely rendered book than a print-to-PDF HTML page.
  
  For a file to be rendered, it has to be configured in the `doctoolchainConfig.groovy` file.
  There you will find a section that looks like this:
  
  ```
  inputFiles = [
  