DAOS-15636 doc: Include engine log mask values in config file (#17551) (#17558)

Engine log_mask values are different from those for the control
log mask.

Signed-off-by: Kris Jacque <[email protected]>

Author: kjacque

utils/config/daos_server.yml

@@ -364,7 +364,10 @@
 #  # Force specific debug mask for the engine at start up time.
 #  # By default, just use the default debug mask used by DAOS.
 #  # Mask specifies minimum level of message significance to pass to logger.
-#
+#  # Currently supported values:
+#  #   DEBUG, DBUG (alias for DEBUG), INFO, NOTE, WARN, ERROR, ERR (alias for ERROR), CRIT, ALRT,
+#  #   FATAL, EMRG, EMIT
+#  #
 #  # default: ERR
 #  log_mask: INFO
 #
@@ -528,7 +531,10 @@
 #  # Force specific debug mask for the engine at start up time.
 #  # By default, just use the default debug mask used by DAOS.
 #  # Mask specifies minimum level of message significance to pass to logger.
-#
+#  # Currently supported values:
+#  #   DEBUG, DBUG (alias for DEBUG), INFO, NOTE, WARN, ERROR, ERR (alias for ERROR), CRIT, ALRT,
+#  #   FATAL, EMRG, EMIT
+#  #
 #  # default: ERR
 #  log_mask: INFO
 #