Add ClueCon URL

docs/GivingBack

@@ -30,4 +30,4 @@ company receives priority support.
 
 Encourage your company to sponsor ClueCon; in addition to helping out
 the project, you'll be exposed to a great pool of people to partner
-with, sell to, and recruit from.
+with, sell to, and recruit from. ( https://ClueCon.com )