remove unused code

src/index.ts

@@ -132,7 +132,6 @@ abstract class ChartwerkPod<T extends TimeSerie, O extends Options> {
   protected deltaYTransform = 0;
   protected debouncedRender = debounce(this.render.bind(this), 100);
 
-  protected svgElParams: SvgElParams;
   // components
   protected grid: Grid;