docs: update working solutions to watch a package inside node_modules/

The current `server.watch` docs aren't accurate and the solution
proposed just doesn't work. See vitejs#8619

There is a different workaround in the issue using a custom Vite plugin
if you're using the Vite dev server, vitejs#8619 (comment)

docs/config/build-options.md

@@ -245,6 +245,12 @@ Limit for chunk size warnings (in kbs). It is compared against the uncompressed
 
 Set to `{}` to enable rollup watcher. This is mostly used in cases that involve build-only plugins or integrations processes.
 
+::: warning Watch a package inside `node_modules/`
+
+It's currently not possible to watch a package inside `node_modules/` until https://github.com/vitejs/vite/issues/8619 is resolved. There isn't a known workaround for Vite build yet.
+
+:::
+
 ::: warning Using Vite on Windows Subsystem for Linux (WSL) 2
 
 There are cases that file system watching does not work with WSL2.

docs/config/server-options.md

@@ -173,23 +173,32 @@ The error that appears in the Browser when the fallback happens can be ignored.
 
 File system watcher options to pass on to [chokidar](https://github.com/paulmillr/chokidar#api).
 
-The Vite server watcher skips `.git/` and `node_modules/` directories by default. If you want to watch a package inside `node_modules/`, you can pass a negated glob pattern to `server.watch.ignored`. That is:
+The Vite server watcher skips `.git/` and `node_modules/` directories by default.
+
+::: warning Watch a package inside `node_modules/`
+
+It's currently not possible to watch a package inside `node_modules/` until https://github.com/vitejs/vite/issues/8619 is resolved.
+
+You can work around this by adding the following to your `vite.config.js`:
 
 ```js
 export default defineConfig({
-  server: {
-    watch: {
-      ignored: ['!**/node_modules/your-package-name/**'],
+  plugins: [
+    {
+      name: 'watch-node-modules',
+      configureServer: (server: ViteDevServer): void => {
+        server.watcher.options = {
+          ...server.watcher.options,
+          ignored: [/node_modules\/(?!my-package-name).*/, '**/.git/**'],
+        }
+      },
     },
-  },
-  // The watched package must be excluded from optimization,
-  // so that it can appear in the dependency graph and trigger hot reload.
-  optimizeDeps: {
-    exclude: ['your-package-name'],
-  },
+  ],
 })
 ```
 
+:::
+
 ::: warning Using Vite on Windows Subsystem for Linux (WSL) 2
 
 When running Vite on WSL2, file system watching does not work when a file is edited by Windows applications (non-WSL2 process). This is due to [a WSL2 limitation](https://github.com/microsoft/WSL/issues/4739). This also applies to running on Docker with a WSL2 backend.