Add indexed, independent scroll text layers

Add multiple scrolling text layers. examples:

int myLayer = matrix.initNewScrollLayer();
int mySecondLayer=matrix.initNewScrollLayer();
matrix.setScrollOffsetFromEdge(0,myLayer);
matrix.setScrollOffsetFromEdge(20,mySecondLayer);
matrix.setScrollMode(bounceReverse,mySecondLayer);
matrix.scrollText(“1st Layer”,-1,myLayer);
matrix.scrollText(“2nd Layer”,-1,mySecondLayer);
delay(1000 * 10);
matrix.updateScrollText(“Updated Layer”, myLayer);