docs: Add firstname.club to the showcase

docs/content/showcase/firstnameclub.md

@@ -0,0 +1,13 @@
+---
+date: 2017-03-31T22:36:12+03:00
+description: "Multilingual webiste. Size 20GB, build time 25 mins. Cloudflare, s3, bootstrap 4"
+license: ""
+licenseLink: ""
+sitelink: https://firstname.club
+sourceLink: https://github.com/spf13/spf13.com
+tags:
+- data
+- website
+thumbnail: /img/firstnameclub.png
+title: firstname club
+---