Update 08.2-Chords.md

Update to match current behavior of `play_pattern_timed`

Author: CUBICinfinity

etc/doc/tutorial/08.2-Chords.md

@@ -46,19 +46,28 @@ play_pattern_timed chord(:E3, :m13), [0.25, 0.5]
 This is the equivalent to:
 
 ```
-play 52
+play 52, sustain: 0.25
 sleep 0.25
-play 55
+play 55, sustain: 0.5
 sleep 0.5
-play 59
+play 59, sustain: 0.25
 sleep 0.25
-play 62
+play 62, sustain: 0.5
 sleep 0.5
-play 66
+play 66, sustain: 0.25
 sleep 0.25
-play 69
+play 69, sustain: 0.5
 sleep 0.5
-play 73
+play 73, sustain: 0.25
+sleep 0.25
 ```
 
 Which would you prefer to write?
+
+Note that `play_pattern_timed` changes the sustain of the notes to 
+fill the times. You can remove this behavior by setting the 
+`sustain:` opt to `0`:
+
+```
+play_pattern_timed chord(:E3, :m13), [0.25, 0.5], sustain: 0
+```