Add note about IPBan

Author: jjxtra

README.md

@@ -1,4 +1,6 @@
 # IPBanProSDK
 This is the C# / .NET Core IPBan Pro API and Applications Integration. Use this code to bind to the IPBan Pro API and web admin utility.
 
+In order to build and run you need to also place IPBan in a sibling folder (https://github.com/DigitalRuby/IPBan). Eventually this will be a nuget package link.
+
 Learn more at https://ipban.com