update documentation

data/yad.1

@@ -572,10 +572,10 @@ Special column names \fI@fore@\fP, \fI@back@\fP and \fI@font@\fP sets correspond
 Values of those columns don't show in results.
 .TP
 .B \-\-checklist
-Use check boxes for first column.
+Use check boxes for the first column. Output checked rows instead of selected rows. Disable multiple selection.
 .TP
 .B \-\-radiolist
-Use radio toggle for first column.
+Same as \fI\-\-checklist\fP but with a radio toggle for the first column.
 .TP
 .B \-\-separator=\fISTRING\fP
 Set output separator characters.