Add a comment of why we need to fix index length

main.go

@@ -26,6 +26,8 @@ type m3u8Json struct {
 	Manifest interface{}
 }
 
+// by default m3u8 package creates a 1024 length slice. We need to update the
+// len of the slice so we don't get null when doing json marshal
 func nilIndex(input []*m3u8.MediaSegment) int {
 	output := -1