docs: Add guide for Nest Devtools

Relates to #2568

docs/docs/guides/developer-guide/nest-devtools/index.md

@@ -0,0 +1,74 @@
+---
+title: "Nest Devtools"
+---
+
+The NestJS core team have built a [powerful set of dev tools](https://docs.nestjs.com/devtools/overview) which can be used to inspect, analyze and debug NestJS applications.
+Since a Vendure server is a NestJS application, these tools can be used to debug your Vendure application.
+
+:::note
+Nest Devtools is a paid service. You can [sign up for a free trial](https://devtools.nestjs.com/).
+:::
+
+## Installation
+
+First you'll need to install the `@nestjs/devtools-integration` package:
+
+```bash
+npm i @nestjs/devtools-integration
+```
+
+## Configuration
+
+Next you need to create a plugin which imports the `DevToolsModule` and adds it to the `imports` array:
+
+```ts title="src/plugins/devtools/devtools-plugin.ts"
+import { VendurePlugin } from '@vendure/core';
+import { DevtoolsModule } from '@nestjs/devtools-integration';
+
+@VendurePlugin({
+    imports: [
+        DevtoolsModule.register({
+            // The reason we are checking the NODE_ENV environment 
+            // variable here is that you should never use this module in production!
+            http: process.env.NODE_ENV !== 'production',
+        }),
+    ],
+})
+class DevtoolsPlugin {}
+```
+
+Now we need to add this plugin to the `plugins` array in the `VendureConfig`. We need to make sure we are
+only adding it to the server config, and not the worker, otherwise we will get a port config when
+running the server and worker at the same time.
+
+Lastly we must set the `snapshot` option when bootstrapping the server. Note: this is only possible
+with Vendure v2.2 or later.
+
+```ts title="src/index.ts"
+import { bootstrap } from '@vendure/core';
+import { config } from './vendure-config';
+
+const configWithDevtools = {
+    ...config,
+    plugins: [
+        ...config.plugins,
+        DevtoolsPlugin,
+    ],
+};
+
+bootstrap(configWithDevtools, {
+    nestApplicationOptions: { snapshot: true } 
+})
+    .catch(err => {
+        console.log(err);
+        process.exit(1);
+    });
+```
+
+## Usage
+
+Now you can start the server, and navigate to [devtools.nestjs.com](https://devtools.nestjs.com/) to start view your
+Vendure server in the Nest Devtools dashboard.
+
+![Nest Devtools graphql explorer](./nest-devtools-graph.webp)
+![Nest Devtools bootstrap performance](./nest-devtools-bootstrap-perf.webp)

docs/sidebars.js

@@ -101,6 +101,7 @@ const sidebars = {
                 'guides/developer-guide/stand-alone-scripts/index',
                 'guides/developer-guide/translations/index',
                 'guides/developer-guide/uploading-files/index',
+                'guides/developer-guide/nest-devtools/index',
             ],
             customProps: {
                 icon: icon.angleBrackets,