Adds sample index to readme.
Completes #2497
Completes #2536
## Pre-launch Checklist
- [x] I read the [Flutter Style Guide] _recently_, and have followed its
advice.
- [x] I signed the [CLA].
- [x] I read the [Contributors Guide].
- [x] I updated/added relevant documentation (doc comments with `///`).
- [x] All existing and new tests are passing.
A collection of open source samples that illustrate best practices for
[Flutter](https://flutter.dev).
## Visual samples index
The easiest way to browse through the samples in this repo (as well as a few others!)
is the [visual samples index](https://flutter.github.io/samples).
## Tip: minimize download size
As this repository is quite big, you can use svn to download a single example.
[Flutter].
## Index
### Quickstarts
* [`asset_transformation`] - Demonstrates how to transform images' color scales and formats.
* [`background_isolate_channels`] - Demonstrates how to use long-lived isolates.
* [`code_sharing`] - Demonstrates how to share business logic between Flutter client and Dart server using [`package:shelf`] )
* [`context_menus`] - This sample shows how to create and customize cross-platform context menus, such as the text selection toolbar on mobile or the right click menu on desktop.
* [`desktop_photo_search`] - Demonstrates desktop features in both Material and FluentUI design systems.
* [`dynamic_theme`] - A developer sample demonstrating how to call on-device Flutter APIs based on output from the Gemini API.
* [`form_app`] - A sample demonstrating different types of forms and best practices.
* [`game_template`] - (**note: deprecated!**) A starter game in Flutter with all the bells and whistles of a mobile (iOS & Android) game.
* [`gemini_tasks`] - A developer sample written in Flutter demonstrating how to interact with a to-do list in natural language using the Gemini API.
* [`google_maps`] - Demonstrates the Google Maps for Flutter plugin.
* [`infinite_list`] - A Flutter sample app that shows an implementation of the "infinite list" UX pattern.
* [`isolate_example`] - A sample application that demonstrate best practices when using [isolates].
* [`navigation_and_routing`] - A sample that shows how to use [go_router] API to handle common navigation scenarios.
* [`place_tracker`] - A sample place tracking app that uses the [google_maps_flutter plugin].
* [`platform_design`] - This sample project shows a Flutter app that maximizes application code reuse while adhering to different design patterns on Android and iOS.
* [`provider_counter`] - The starter Flutter application, but using [package:provider] to manage state.
* [`provider_shopper`] - A Flutter sample app that shows a state management approach using [package:provider].
* [`simple_shader`] - A simple [Flutter fragment shaders] sample project.
* [`simplistic_calculator`] - A calculator to demonstrate a simple start for a desktop Flutter app.
* [`simplistic_editor`] - This sample text editor showcases the use of [TextEditingDeltas] and a DeltaTextInputClient to expand and contract styled ranges of text.
* [`testing_app`] - A sample app that shows different types of testing in Flutter.
* [`web_embedding`] - This directory contains examples of how to embed Flutter in web apps (without iframes).
* [`element_embedding_demo`] - Modifies the index.html of a flutter app so it is launched in a custom hostElement. This is the most basic embedding example.
* [`ng-flutter`] - A simple Angular app (and component) that replicates the above example, but in an Angular style.
### Native platform samples
* [`add-to-app`] - Collection of samples that demonstrate embedding Flutter a view into a native app.
* [`fullscreen`] — Embeds a full screen instance of
Flutter into an existing iOS or Android app.
* [`prebuilt_module`] — Embeds a full screen
instance of Flutter as a prebuilt library that can be loaded into an existing
iOS or Android app.
* [`plugin`] — Embeds a full screen Flutter instance that
is using plugins into an existing iOS or Android app.
* [`books`] — Mimics a real world use-case of embedding Flutter into an
existing Android app and demonstrates using [Pigeon] to communicate between Flutter and
the host application.
* [`multiple_flutters`] — Shows the usage of the Flutter
Engine Group APIs to embed multiple instances of Flutter into an existing app
with low memory cost.
* [`android_view`] — Shows how to integrate a Flutter
add-to-app module at a view level for Android.
* [`android_splash_screen`]
* [`ios_app_clip`]
* [`platform_channels`] - A sample app which demonstrates how to use MethodChannel, EventChannel, BasicMessageChannel and MessageCodec in Flutter.
* [`platform_view_swift`] - A Flutter sample app that combines a native iOS UIViewController with a full-screen Flutter view.
### Demo galleries
* [`animations`] - Showcases Flutter's animation features
* [`material_3_demo`] - showcases [Material 3] features in the Flutter Material library.
### Demo apps
* [`compass_app`] - A sample application that implements MVVM architecture.
* [`deeplink_store_example`] - A demo app that implements deep-linking with go_router.
* [`veggie_seasons`] - A demo application.
## Flutter sample code
Samples are **correct and concise code** that developers
can **quickly understand** and **easily reuse** with minimal side effects.
Samples teach developers how to be successful using Flutter and Dart.
They are maintained on an ongoing basis
to reflect changing APIs and best practices.
### Types of samples
There are two types of sample code in this repository:
* **Quickstarts** provide a starting point to extend. They answer the question,
"What is the minimal amount of code needed to implement this feature?"
* **Demo apps** are meant to be built and ran. They demo the _product_,
not how to write code.
A majority of samples in this repository are quickstarts.
## Usage
Every sample in this repo is fully runnable. To run an example,
use `flutter run` inside that example's directory.
See the [getting started guide] to install the `flutter` tool.
> [!IMPORTANT]
> If you want to run an add-to-app sample, there are additional requirements.
> We suggest reading the [add-to-app documentation].
### Tip: minimize download size
As this repository is quite big, you can use
[svn] to download a single example.
For example:
```
svn co https://github.com/flutter/samples/trunk/provider_shopper