anchor.diff:  ----
   font:
     catalog:
  +    merge: false # set value to true to merge catalog with theme you're extending
       Roboto:
         normal: roboto-normal.ttf
         italic: roboto-italic.ttf
  
positive.code: 
  ==== Declaring Your Font
  
  Next, declare the font under the `font-catalog` key at the top of your theme file, giving it a unique key (e.g., `Roboto`).
  
  [source,yaml]
  ----
  font:
    catalog:
      Roboto:
        normal: roboto-normal.ttf
        italic: roboto-italic.ttf
  
negative.code: 
  === Custom Fonts
  
  The limited character set of WINANSI, or the plain look of the built-in or bundled fonts, may motivate you to incorporate your own fonts.
  Custom fonts can enhance the look of your PDF theme substantially.
  
  IMPORTANT: In order for a third-party font to work properly with Prawn (and hence Asciidoctor PDF), several modifications are required.
  