Fix link

README.md

@@ -7,7 +7,7 @@ Utility functions for [_AudioBuffers_](https://github.com/audiojs/audio-buffer)
 * [util.clone(buf)](#utilclonebuffer)
 * [util.copy(buf, dst, start?)](#utilcopyfrombuffer-tobuffer-offset0)
 * [util.slice(buf, start?, end?)](#utilslicebuffer-start0-end-0)
-* [util.subbuffer(buf, start?, end?)](#utilsubbufferbuffer-start0-end-0)
+* [util.subbuffer(buf, start?, end?, ch?)](#utilsubbufferbuffer-start0-end-0-channels)
 * [util.concat(a, b, ...)](#utilconcatbuffer1-buffer2-buffer3-buffern-)
 * [util.repeat(buf, n)](#utilrepeatbuffer-times)
 * [util.reverse(src, dst?, start?, end?)](#utilreversebuffer-target-start0-end-0)