Link card is a card, when clicked, the user goes to the specified link.
Use it to refer to your articles on other resources, to your new works (wherever they are posted: Github, Dribbble or anything else), to the certificates you received, and in general, to whatever is more convenient give a link.
If you have any problems with the Chronoblog, or you have interesting ideas, write to the github issue: github.com/Chronoblog/gatsby-theme-chronoblog/issues
You can also contact me on Twitter: twitter.com/Ganevru
About Free Code Camp Full Stack Development Certification: guide.freecodecamp.org/meta/free-code-camp-full-stack-development-certification