lavr doxy: add version.h to the lavr group

libavresample/version.h

@@ -19,6 +19,12 @@
 #ifndef AVRESAMPLE_VERSION_H
 #define AVRESAMPLE_VERSION_H
 
+/**
+ * @file
+ * @ingroup lavr
+ * Libavresample version macros.
+ */
+
 #define LIBAVRESAMPLE_VERSION_MAJOR  1
 #define LIBAVRESAMPLE_VERSION_MINOR  1
 #define LIBAVRESAMPLE_VERSION_MICRO  0