Reduce default rows but add button to add row

src/App.svelte

@@ -6,7 +6,7 @@ import FormulaS from "./FormulaS.svelte";
     import RowWorkItem from "./RowWorkItem.svelte";
     import SumRow from "./SumRow.svelte";
 
-    const NUMBER_OF_WORKPACKAGES = 10;
+    const NUMBER_OF_WORKPACKAGES = 8;
 
     let workPackages: WorkPackage[] = []
     export let r: number = 4;
@@ -50,6 +50,7 @@ import FormulaS from "./FormulaS.svelte";
             <SumRow {workPackages} u={u} r={r}></SumRow>
         </tbody>
     </table>
+    <button on:click={() => {workPackages = [...workPackages, {a: null, b: null, c: null}];}}>Zeile hinzufügen</button>
 
     <FormulaE workPackages={workPackages} r={r}/>
     <br>