[#18] Update readme file.

Author: Nordes Ménard-Lamarre

README.md

@@ -24,6 +24,8 @@ The plugin is easy to install to your solution. Built using **.Net Standard 2.0*
 Install-Package IdentityServer.LdapExtension
 ```
 
+> Be aware that version 2.0.0 is for version 2.2.x of IdentityServer4. The version that comes after is for the IdentityServer4 2.3.0.
+
 ## Configuration for IdentityServer4 Server
 An easy extension method have been created in order to add the LDAP as a provider to your IdentityServer. For this you simply have to use the `AddLdapUsers<TApplicationUser>(LdapConfigSection, StoreTypeOrCustomStore)`. The configuration has to be provided or it won't work. The configuration is described [here](#IS.AppSettings).