Charts config: Add gauge and pie chart types (#2509)

Those are imported in
974e28e9ba/bundles/org.openhab.ui/web/src/components/widgets/system/oh-chart-component.vue (L47)
and should therefore work.

Signed-off-by: Florian Hotze <florianh_dev@icloud.com>

bundles/org.openhab.ui/web/src/assets/definitions/widgets/chart/index.js

@@ -199,7 +199,9 @@ const seriesParameters = [
 const seriesTypesLabels = {
   line: 'Line',
   bar: 'Bar',
+  gauge: 'Gauge',
   heatmap: 'Heatmap',
+  pie: 'Pie',
   scatter: 'Scatter'
 }