Add Yangyong Wu to CREDITS

This name is inferred from the contributor's Github account email
(interpreted using the standard given-family name Chinese convention).

Change-Id: I2285a62c3332d562f44c5087b296e4ea2d61200e
diff --git a/docs/CREDITS b/docs/CREDITS
index e1d7999..eaaad5b 100644
--- a/docs/CREDITS
+++ b/docs/CREDITS
@@ -677,6 +677,7 @@
 Alex Wallis
 Christian Soffke
 Juan Gonzalez
+Yangyong Wu
 
 The libmad team
 The wavpack team