Merge pull request #1911 from Selleo/master

docs: add selleo.com to the who-uses section

Author: kamilmysliwiec

content/discover/who-uses.json

@@ -243,6 +243,7 @@
     "https://datenlotse.org",
     "https://bemum.co",
     "https://weoptimeye.ai",
-    "https://nemovote.com"
+    "https://nemovote.com",
+    "https://selleo.com"
   ]
 }