Clarify paddings count into number of frames.

Author: Rot127

README.md

@@ -59,6 +59,7 @@ Then the next frame size, followed by the frame data.
 
 If the frame size is 0, there is no frame data. It is only there as padding to fill the
 TOC entry to the number of required elements.
+Padding entries are still counted into the total number of frames.
 
 The TOC index is stored at the end.