docs: add next js with app router example (#7552)

* move the existing example to with-script-in-browser

* Add example with next js app router

* disable ssr for excalidraw client comp

* typo

* update output dir

* don't include nextjs example in tsconfig

* remove meta.json

* lint

* remove example.ts

* port

* move the examples outside packages and use the deps as workspaces in examples

* update gitignore

* fix example

* update path of build dir

* fix

* fix scripts

* try local path

* fix

* update commands

* fix

* fix

* fix script

* skip ts

* disable ts

* add vercel.json

* install

* update tsconfig

* fix lint

* remove console.log

* lets see if this works

* revert

* remove ts nocheck

* add types and some utils in nextjs example

* fix types

* updatw example and remove nextjs dynamic syntax so we don't import excal twice

* move both examples to workspaces and create generic example to be used by browser and next js both

* copy the static assets to nextjs

* fix ts config

* render custom menu items

* fix custom footer

* fix types in browser example

* use regular imports for importing excal and import it using dynamic next js in app router instead

* Add example for pages router

* fix css discrepancies

* fix css

* configure output dir

* fix

* fix css

* rename to with-nextjs

* move components to examples/excalidraw/components

examples/excalidraw/components/MobileFooter.tsx

@@ -0,0 +1,27 @@
+import { ExcalidrawImperativeAPI } from "@excalidraw/excalidraw/dist/excalidraw/types";
+import CustomFooter from "./CustomFooter";
+import type * as TExcalidraw from "@excalidraw/excalidraw";
+
+const MobileFooter = ({
+  excalidrawAPI,
+  excalidrawLib,
+}: {
+  excalidrawAPI: ExcalidrawImperativeAPI;
+  excalidrawLib: typeof TExcalidraw;
+}) => {
+  const { useDevice, Footer } = excalidrawLib;
+
+  const device = useDevice();
+  if (device.editor.isMobile) {
+    return (
+      <Footer>
+        <CustomFooter
+          excalidrawAPI={excalidrawAPI}
+          excalidrawLib={excalidrawLib}
+        />
+      </Footer>
+    );
+  }
+  return null;
+};
+export default MobileFooter;