Fix #687: Include MIDI swing script in default distribution

Documentation/changes.tely

Index: Documentation/changes.tely
diff --git a/Documentation/changes.tely b/Documentation/changes.tely
index 06ec2ea54f2f35c45415e3be2e202d7150719229..0469f2ca6b070cc86bbb746a462d610a71454603 100644
--- a/Documentation/changes.tely
+++ b/Documentation/changes.tely
@@ -62,6 +62,26 @@ which scares away people.
 @end ignore
 
 
+@item
+Swing and irregular rhythmic patterns may now be applied to
+music expressions made of regular durations, which may be
+used to render inequal rhythmic interpretation in MIDI.
+@lilypond[verbatim,quote]
+\include "swing.ly"
+<<
+  \new Staff \with {
+    instrumentName = "ordinary"
+  } \repeat unfold 8 c'8
+  \new Staff \with {
+    instrumentName = "with swing"
+  } \repeat unfold 4 \tripletFeel 8 { c'8 c' }
+  \new Staff \with {
+    instrumentName = "tuplets"
+  } \tuplet 3/2 4 \repeat unfold 12 c'8
+>>
+@end lilypond
+
+
 @item
 A very short fermata and Henze variants of long and short fermatas
 have been added.