Update readme to highlight interaction between "Authenticated" user g…

…roup and Permission checking (#210)

* Update Readme to mention "Authenticated" user group

* Slightly change the wording of the readme update

* Update README.adoc

Co-authored-by: Mark Waite <mark.earl.waite@gmail.com>

---------

Co-authored-by: Firahs Chebbo <fchebbo@blizzard.com>
Co-authored-by: Mark Waite <mark.earl.waite@gmail.com>

README.adoc

@@ -132,6 +132,9 @@ You can configure to allow Copy Artifact to access source jobs in the following
 * <<CopyArtifactPlugin-Specifyprojectswhocancopyartifacts,Configure source jobs specifying jobs who can copy artifacts.>>
 * <<CopyArtifactPlugin-Authorizebuildsasauser,Authorize builds as a user.>>
 
+The message will not be encountered if the "Authenticated" user group has the "job/read" permission enabled.
+If this issue appears on your controller, check if this configuration has recently changed.
+
 [[CopyArtifactPlugin-Specifyprojectswhocancopyartifacts]]
 ==== Specify projects who can copy artifacts