docs: mention use of ListR feature in ls docs

Author: vyv03354

cmd/ls/lshelp/lshelp.go

@@ -26,6 +26,10 @@ Note that |ls| and |lsl| recurse by default - use |--max-depth 1| to stop the re
 The other list commands |lsd|,|lsf|,|lsjson| do not recurse by default -
 use |-R| to make them recurse.
 
+List commands prefer a recursive method that uses more memory but fewer
+transactions by default. Use |--disable ListR| to suppress the behavior.
+See [|--fast-list|](/docs/#fast-list) for more details.
+
 Listing a nonexistent directory will produce an error except for
 remotes which can't have empty directories (e.g. s3, swift, or gcs -
 the bucket-based remotes).`, "|", "`")