feat: added small example of hierarchy usage

examples/src/basic/hierarchy.ts

@@ -0,0 +1,23 @@
+import {html, render} from 'lit-html';
+import {GraferController} from '../../../src/mod';
+
+export async function hierarchy(container: HTMLElement): Promise<void> {
+    render(html`<canvas class="grafer_container"></canvas><mouse-interactions></mouse-interactions>`, container);
+    const canvas = document.querySelector('.grafer_container') as HTMLCanvasElement;
+
+    const points = {
+        data: [
+            { id: 0, x: 0, y: 0 },
+            { id: 1, x: 2, y: 0, parentId: 0 },
+            { id: 2, x: 2, y: 0, parentId: 1 },
+        ],
+    };
+    const nodes = {
+        ...points,
+        mappings: {
+            point: (d: any): number => d.id,
+        },
+    };
+
+    new GraferController(canvas, { points, layers: [{nodes}] });
+}

examples/src/basic/mod.ts

@@ -4,3 +4,4 @@ export * from './nodeColors';
 export * from './edgeColors';
 export * from './nodeRadius';
 export * from './nodeID';
+export * from './hierarchy';