add a bottom padding when the bottom area is expanded

- attach a ''resetBottomPadding" event to the album header component
- add function documentation to the header and albumview components.

src/components/shared/SongItem.vue

@@ -127,7 +127,6 @@ function emitUpdate(track: Track) {
   text-align: left;
   gap: $small;
   user-select: none;
-  -moz-user-select: none;
 
   @include tablet-landscape {
     grid-template-columns: 1.5rem 1.5fr 1fr 1fr 2.5rem;