Add docs for Next.js SDK option autoInstrumentServerFunctions

Author: Luca Forstner

src/platforms/javascript/guides/nextjs/manual-setup.mdx

@@ -184,6 +184,7 @@ const moduleExports = {
     // sections below for information on the following options:
     //   - disableServerWebpackPlugin
     //   - disableClientWebpackPlugin
+    //   - autoInstrumentServerFunctions
     //   - hideSourceMaps
     //   - widenClientFileUpload
     //   - transpileClientSDK
@@ -242,6 +243,20 @@ module.exports = withSentryConfig(moduleExports);
 
 In that case you can also skip the `sentry-cli` configuration step below.
 
+### Automatically Instrument API Routes And Data Fetching Methods
+
+_(New in version TODO)_
+
+The SDK provides an option to automatcally instrument API routes and [Next.js Data Fetching Methods](https://nextjs.org/docs/basic-features/data-fetching/overview) with error and performance monitoring, removing the need to manually wrap API routes in `withSentry`.
+
+```javascript {filename:next.config.js}
+const moduleExports = {
+  sentry: {
+    autoInstrumentServerFunctions: true,
+  },
+};
+```
+
 ### Use `hidden-source-map`
 
 _(New in version 6.17.1, will default to `true` in 8.0.0 and beyond.)_