docs/man/nut-scanner.txt: document that currently different IP range …

…scans do not parallelize together [networkupstools#2244]

Signed-off-by: Jim Klimov <[email protected]>

docs/man/nut-scanner.txt

@@ -122,6 +122,12 @@ range, turning those two into single-IP queries.
 Also note that some buses require IP address(es) to scan, and others have a
 different behavior when exactly no addresses are specified (it is not currently
 possible to mix the two behaviors in one invocation of the `nut-scanner` tool).
++
+Finally note that currently even if multi-threaded support is available, each
+range specification is a separate fan-out of queries constrained by the timeout.
+Requests to scan many single IP addresses will take a while to complete, much
+longer than if they were a single range. This will be hopefully fixed in later
+releases.
 
 *-t* | *--timeout* 'timeout'::
 Set the network timeout in seconds. Default timeout is 5 seconds.