Add FxSiteCompat.com to Showcase

docs/content/showcase/fxsitecompat.md

@@ -0,0 +1,15 @@
+---
+date: 2014-08-26T19:40:00-04:00
+description: Multilingual, community documentation and blog site
+license: ""
+licenseLink: ""
+sitelink: https://www.fxsitecompat.com/
+sourceLink: https://github.com/fxsitecompat/www.fxsitecompat.com
+tags:
+- community
+- documentation
+- translation
+thumbnail: /img/fxsitecompat-tn.png
+title: Firefox Site Compatibility
+---
+