I open any file in these repos in VS Code, and before the first heading the Outline panel shows a block of names: title , numero , date , sesion_fuente , fecha_creacion , description , tags , destacado , slug . This post carries those nine at the top, and will gain a tenth once it's published. Yesterday I asked myself who decided each one. Short answer: nobody, all at once. That block is the frontmatter : a few key: value lines between two --- at the top of a Markdown file. It i...