Added reference to template repo (#279)

* Added reference to template repo

* Updated the repo link for the Flutter template

---------

Co-authored-by: Mike Barnes <michael@journeyapps.com>

Author: bean1352

client-sdk-references/flutter.mdx

@@ -23,6 +23,13 @@ import FlutterWatch from '/snippets/flutter/basic-watch-query.mdx';
   </Card>
 </CardGroup>
 
+### Quickstart
+
+Get started quickly by using the self-hosted **Flutter** + **Supabase** template
+
+📂 GitHub Repo
+[https://github.com/powersync-community/flutter-powersync-supabase](https://github.com/powersync-community/flutter-powersync-supabase)
+
 ### SDK Features
 
 <SdkFeatures />
@@ -376,4 +383,4 @@ See [Troubleshooting](/resources/troubleshooting) for pointers to debug common i
 
 ## Supported Platforms
 
-See [Supported Platforms -> Dart SDK](/resources/supported-platforms#dart-sdk).
+See [Supported Platforms -> Dart SDK](/resources/supported-platforms#dart-sdk).