feat: move Hands-on start page to the Kotlin docs (JetBrains#3578)

* update: move Hands-on start page to the Kotlin docs

* update: update docs/topics/kotlin-hands-on.md

Co-authored-by: Danil Pavlov <[email protected]>

* Apply suggestions from code review

Co-authored-by: Sarah Haggarty <[email protected]>

* fix: fix the toc

---------

Co-authored-by: Danil Pavlov <[email protected]>
Co-authored-by: Sarah Haggarty <[email protected]>

docs/kr.tree

@@ -394,6 +394,7 @@
         <toc-element href="https://play.kotlinlang.org/byExample/overview" toc-title="Kotlin by example"/>
         <toc-element id="koans.md"/>
         <toc-element href="https://hyperskill.org/tracks?category=4&amp;utm_source=jbkotlin_hs&amp;utm_medium=referral&amp;utm_campaign=kotlinlang-docs&amp;utm_content=button_1&amp;utm_term=22.03.23" toc-title="Kotlin Core track"/>
+        <toc-element id="kotlin-hands-on.md" toc-title="Kotlin hands-on"/>
         <toc-element id="kotlin-tips.md"/>
         <toc-element id="books.md"/>
         <toc-element id="advent-of-code.md" toc-title="Advent of Code puzzles"/>

docs/topics/home.xml

@@ -50,7 +50,7 @@
                     <a href="koans.md" description="Programming exercises to get you familiar with Kotlin">Koans</a>
                     <a href="https://hyperskill.org/tracks?category=4&amp;utm_source=jbkotlin_hs&amp;utm_medium=referral&amp;utm_campaign=kotlinlang-docs&amp;utm_content=button_1&amp;utm_term=22.03.23" description="Kotlin Core track by JetBrains Academy">JetBrains Academy</a>
                     <a href="advent-of-code.md" description="Code puzzles in idiomatic Kotlin">Advent of Code</a>
-                    <a href="https://play.kotlinlang.org/hands-on/overview" description="Complete long-form tutorials to fully grasp a technology">Hands-on tutorials</a>
+                    <a href="kotlin-hands-on.md" description="Complete long-form tutorials to fully grasp a technology">Hands-on tutorials</a>
                     <a href="edu-tools-learner.md"
                        description="An IDE plugin for learning and teaching programming languages">JetBrains Academy in
                         IntelliJ IDEA</a>

docs/topics/kotlin-hands-on.md

@@ -0,0 +1,76 @@
+[//]: # (title: Kotlin hands-on)
+
+A series of hands-on tutorials where you can create applications with Kotlin using a variety of different technologies and targeting multiple platforms.
+The exercises are divided into a series of steps, walking you through each section.
+
+## Building Reactive Spring Boot applications with Kotlin coroutines and RSocket
+
+Build a simple chat application using Spring Boot and Kotlin, and learn about the benefits of using Kotlin for server-side development from a syntax perspective.
+
+[**Start**](https://spring.io/guides/tutorials/spring-webflux-kotlin-rsocket/)
+
+## Building web applications with React and Kotlin/JS
+
+Create a React Application using Kotlin/JS, and see how you can leverage Kotlin's type system, library ecosystem, and interoperability features.
+
+[**Start**](js-react.md)
+
+## Building web applications with Spring Boot and Kotlin
+
+Build a sample blog application by combining the power of Spring Boot and Kotlin.
+
+[**Start**](https://spring.io/guides/tutorials/spring-boot-kotlin/)
+
+## Creating HTTP APIs with Ktor
+
+Create a backend API for your application that responds to HTTP requests.
+
+[**Start**](https://ktor.io/docs/creating-http-apis.html)
+
+## Creating a WebSocket chat with Ktor
+
+Create a simple Chat application using Ktor including both a JVM server and a JVM client.
+
+[**Start**](https://ktor.io/docs/creating-web-socket-chat.html)
+
+## Creating an interactive website with Ktor
+
+Learn how to serve files, use templating engines such as Freemarker and the kotlinx.html DSL, and work with form input from Ktor.
+
+[**Start**](https://ktor.io/docs/creating-interactive-website.html)
+
+## Building a full stack web app with Kotlin Multiplatform
+
+Create an application with Kotlin/JVM and Kotlin/JS, and explore topics around code sharing, serialization, server- and client-side development.
+
+[**Start**](multiplatform-full-stack-app.md)
+
+## Introduction to Kotlin coroutines and channels
+
+Learn about coroutines in Kotlin and how you can communicate between them using channels.
+
+[**Start**](coroutines-and-channels.md)
+
+## Introduction to Kotlin/Native
+
+Create a simple HTTP client that can run natively on multiple platforms using Kotlin/Native and libcurl.
+
+[**Start**](native-app-with-c-and-libcurl.md)
+
+## Introduction to Kotlin/Native concurrency
+
+Learn about the concurrency model in Kotlin/Native, and how to work with state in a multithreaded environment.
+
+[**Start**](multiplatform-mobile-concurrency-overview.md)
+
+## Kotlin Multiplatform: networking and data storage
+
+Learn how to create a mobile application for Android and iOS using Kotlin Multiplatform with Ktor and SQLDelight.
+
+[**Start**](multiplatform-mobile-ktor-sqldelight.md)
+
+## Targeting iOS and Android with Kotlin Multiplatform
+
+Learn how to create a mobile application that can target both iOS and Android using Kotlin Multiplatform.
+
+[**Start**](multiplatform-mobile-create-first-app.md)

docs/topics/learning-materials-overview.md

@@ -12,6 +12,6 @@ You can use the following materials and resources for learning Kotlin:
 * [Kotlin books](books.md) – find books we've reviewed and recommend for learning Kotlin.
 * [Kotlin tips](kotlin-tips.md) – watch short videos where the Kotlin team shows you how to use Kotlin in a more efficient and idiomatic way, so you can have more fun when writing code.
 * [Advent of Code puzzles](advent-of-code.md) – learn idiomatic Kotlin and test your language skills by completing short and fun tasks.
-* [Kotlin hands-on tutorials](https://play.kotlinlang.org/hands-on/overview) – complete long-form tutorials to fully grasp a technology. These tutorials guide you through a self-contained project related to a specific topic.
+* [Kotlin hands-on tutorials](kotlin-hands-on.md) – complete long-form tutorials to fully grasp a technology. These tutorials guide you through a self-contained project related to a specific topic.
 * [Kotlin for Java Developers](https://www.coursera.org/learn/kotlin-for-java-developers) – learn the similarities and differences between Java and Kotlin in this course on Coursera.
 * [Kotlin documentation in PDF format](kotlin-pdf.md) – read our documentation offline.