lsblk: add note about --sort and --list relation

Signed-off-by: Karel Zak <kzak@redhat.com>

Documentation/TODO

@@ -24,6 +24,9 @@ lscpu
 
 lsblk
 -----
+  - (!) add --tree to force tree output for operations like --sort where the
+    --list is enabled by default.
+
   - currently it does not show mountpoint for all devices in btrfs RAID. It's because
     /proc/#/mountinfo contains reference to the one device only. Maybe we can add some
     btrfs specific code to provide a better output for FS based stacks. Not sure.

misc-utils/lsblk.8

@@ -125,7 +125,7 @@ This option is equivalent to
 Display version information and exit.
 .TP
 .BR \-x , " \-\-sort " \fIcolumn\fP
-Sort output lines by \fIcolumn\fP.
+Sort output lines by \fIcolumn\fP. This option enables \fB\-\-list\fR output.
 .SH NOTES
 For partitions, some information (e.g. queue attributes) is inherited from the
 parent device.