Mention that IMPORTED targets may be created by a find_package call.

Source/cmFindPackageCommand.cxx

@@ -95,7 +95,8 @@ void cmFindPackageCommand::GenerateDocumentation()
     "Finds and loads settings from an external project.  "
     "<package>_FOUND will be set to indicate whether the package was found.  "
     "When the package is found package-specific information is provided "
-    "through variables documented by the package itself.  "
+    "through variables and imported targets documented by the package "
+    "itself.  "
     "The QUIET option disables messages if the package cannot be found.  "
     "The MODULE option disables the second signature documented below.  "
     "The REQUIRED option stops processing with an error message if the "