Tell to use COPY_AS_IS to include additional modules in case of MODUL…

…ES=( 'loaded_modules' )

In default.conf describe that one can use the generic
COPY_AS_IS method to include certain modules
in addition to the currently loaded modules when
MODULES=( 'loaded_modules' ) is specified, see
#2727 (comment)

usr/share/rear/conf/default.conf

@@ -1548,11 +1548,12 @@ LIBS=()
 # automatically included but this may not work in any case
 # (see https://github.com/rear/rear/issues/1355).
 # The setting MODULES=( 'loaded_modules' ) results that
-# only those kernel modules that are currently loaded
-# (so MODULES=( 'loaded_modules' 'additional_module' ) is not supported)
-# get included in the recovery system. This results a noticeable
-# smaller recovery system but on the other hand it means that
-# recovery will only work on same replacement hardware.
+# only those kernel modules that are currently loaded get included
+# in the recovery system so MODULES=( 'loaded_modules' 'additional_module' )
+# is not supported but you may use COPY_AS_IS+=( ...) to include
+# certain modules in addition to the currently loaded modules. This
+# results a noticeable smaller recovery system but on the other hand
+# it means that recovery will only work on same replacement hardware.
 # The very special setting MODULES=( 'no_modules' ) enforces that
 # no kernel modules at all get included in the recovery system
 # regardless of what modules are currently loaded. Usually this