Creating a child theme structure

Let’s create our first child theme by following the present recipe:

1. The first thing before creating a child theme is to make sure that we have the technical name (folder name) of the original theme we want to use. As a practical example, we will work on the classic theme located in the /themes/classic/ folder. Its technical name is classic. We will create a child theme of the classic theme, which we decided to name childclassicwh. So, let’s create the /themes/childclassicwh/ folder to store our child theme files.
2. The only mandatory files needed are the /themes/childclassicwh/config/theme.yml file to define the metadata necessary to describe our child theme, and the /themes/childclassicwh/preview.png file containing the thumb displayed on the theme’s installation and settings BO pages.
3. Let’s focus on the /themes/childclassicwh/config/theme.yml file first and see how to create it. Its mandatory properties will...