first success with x-data-spreadsheet

Signed-off-by: Stephan Richter <s.richter@srsoftware.de>

frontend/src/routes/calc.svelte

@@ -0,0 +1,19 @@
+<script>
+	import { onMount } from 'svelte';
+	import Spreadsheet from "x-data-spreadsheet";
+
+	function load(){
+const s = new Spreadsheet("#example-table")
+  .loadData({}) // load data
+  .change(data => {
+    // save data to db
+  });
+
+// data validation
+s.validate()
+	}
+
+	onMount(load);
+</script>
+
+<div id="example-table"></div>