docs: Add examples

docs/src/examples/dnd.md

@@ -0,0 +1,29 @@
+---
+pageClass: examples
+
+---
+
+# Drag & Drop
+
+Drag and Drop Sidebar handling is not built in but can be implemented with the native HTML Drag and Drop API, as this
+example shows.
+
+## State access
+
+This example shows another key feature of Vue Flow. You can initialize the Flow state at any point before the Vue Flow
+is actually mounted. This can be achieved by using the [`useVueFlow`](/guide/composables.html#usevueflow) composable.
+
+<div class="mt-6">
+  <iframe src="https://codesandbox.io/embed/vue-flow-drag-drop-tpbm7d?eslint=1&fontsize=14&hidenavigation=1&module=%2Fsrc%2Fcomponents%2FFlow.vue&theme=dark"
+    class="hidden dark:block bg-black h-full w-full min-h-[75vh]"
+    title="Vue Flow: Drag & Drop"
+    allow="accelerometer; ambient-light-sensor; camera; encrypted-media; geolocation; gyroscope; hid; microphone; midi; payment; usb; vr; xr-spatial-tracking"
+    sandbox="allow-forms allow-modals allow-popups allow-presentation allow-same-origin allow-scripts"
+  ></iframe>
+  <iframe src="https://codesandbox.io/embed/vue-flow-drag-drop-tpbm7d?eslint=1&fontsize=14&hidenavigation=1&module=%2Fsrc%2Fcomponents%2FFlow.vue&theme=light"
+    class="block dark:hidden h-full w-full min-h-[75vh]"
+    title="Vue Flow: Drag & Drop"
+    allow="accelerometer; ambient-light-sensor; camera; encrypted-media; geolocation; gyroscope; hid; microphone; midi; payment; usb; vr; xr-spatial-tracking"
+    sandbox="allow-forms allow-modals allow-popups allow-presentation allow-same-origin allow-scripts"
+  ></iframe>
+</div>