how to add/modify chart type(e.g. importing 3rd party JS library - google charts/echarts) in Apache Superset? - Superset 0.30.0

Is there any workbook on how to add/modify Apache Superset's chart type? There's need to import 3rd party JS library e.g. Google Charts/Baidu Echarts. The superset I'm using is the latest - v0.30.0.