Updated README for HLS-16
Updated README for HLS-16

file:a/README.md -> file:b/README.md
--- a/README.md
+++ b/README.md
@@ -47,6 +47,7 @@
 	-t [name]	Segment filename prefix
 	-l		Input is a live stream
 	-f		Foreground encoding only (adaptive non-live streams only)
+	-S		Name of a subdirectory to put segments into
 ```