Merge pull request #2239 from joelbarmettlerUZH/patch-2

docs(who-uses): add PolygonSoftware

Author: kamilmysliwiec

content/discover/who-uses.json

@@ -256,6 +256,7 @@
     "https://www.itrio.net",
     "https://alexishr.com",
     "https://dyrector.io",
-    "https://stijlbreuk.nl"
+    "https://stijlbreuk.nl",
+    "https://polygon-software.ch"
   ]
 }