Add medium to Footer

data/siteMetadata.js

@@ -20,6 +20,7 @@ const siteMetadata = {
   linkedin: 'https://www.linkedin.com',
   threads: 'https://www.threads.net',
   instagram: 'https://www.instagram.com',
+  medium: 'https://medium.com',
   locale: 'en-US',
   // set to true if you want a navbar fixed to the top
   stickyNav: false,