Added IDE plugin docs

Author: Mr3zee

README.md

@@ -101,7 +101,12 @@ Check out our [getting started guide](https://kotlin.github.io/kotlinx-rpc) for
 
 ## Configure the project
 
-### Plugin dependencies
+### IDE Plugin
+
+Install [Kotlin External FIR Support](https://plugins.jetbrains.com/plugin/26480-kotlin-external-fir-support?noRedirect=true) IDE plugin. 
+It will ensure that all IDE features of our compiler plugin work properly.
+
+### Gradle plugins
 
 `kotlinx.rpc` provides Gradle plugin `org.jetbrains.kotlinx.rpc.plugin` 
 that will set up code generation in a project.

docs/pages/kotlinx-rpc/rpc.tree

@@ -11,6 +11,7 @@
                  start-page="get-started.topic">
 
     <toc-element topic="get-started.topic"/>
+    <toc-element topic="ide-plugin.topic"/>
     <toc-element topic="plugins.topic"/>
     <toc-element toc-title="Core concepts">
         <toc-element topic="services.topic"/>

docs/pages/kotlinx-rpc/topics/get-started.topic

@@ -41,6 +41,16 @@
             including but not limited to <a href="https://grpc.io">gRPC</a>.
         </p>
     </chapter>
+    <chapter title="IDE Plugin" id="install-ide-plugin">
+        <p>
+            Library uses a Kotlin compiler plugin to generate declarations.
+            To make this work in Intellij-based IDEs,
+            we provide <a href="https://plugins.jetbrains.com/plugin/26480-kotlin-external-fir-support?noRedirect=true">Kotlin External FIR Support</a> plugin.
+        </p>
+        <p>
+            To learn more, see <a href="ide-plugin.topic"/> page
+        </p>
+    </chapter>
     <chapter title="Installation" id="installation">
         <p>Before adding <code>kotlinx.rpc</code> dependencies, you need to configure your project with <a
                 href="https://docs.gradle.org/current/userguide/userguide.html">Gradle</a>.

docs/pages/kotlinx-rpc/topics/ide-plugin.topic

@@ -0,0 +1,26 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE topic
+        SYSTEM "https://resources.jetbrains.com/writerside/1.0/xhtml-entities.dtd">
+<topic xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+       xsi:noNamespaceSchemaLocation="https://resources.jetbrains.com/writerside/1.0/topic.v2.xsd"
+       title="IDE Plugin" id="ide-plugin">
+
+    <p>
+        Library uses a Kotlin compiler plugin to generate declarations.
+        To make this work in Intellij-based IDEs,
+        we provide <a href="https://plugins.jetbrains.com/plugin/26480-kotlin-external-fir-support?noRedirect=true">Kotlin External FIR Support</a> plugin.
+    </p>
+    <p>
+        No additional steps to configure the plugin are required.
+    </p>
+    <p>
+        If you encounter other unexpected limitations or bugs,
+        please <a href="https://github.com/Mr3zee/kotlin-plugins/issues">report</a> them
+    </p>
+    <note>
+        Please note, that the plugin is based on <b>experimental</b> IDE functionality,
+        which means that only newer IDE versions are supported.
+        For full compatibility guides, see the plugin page on the
+        <a href="https://plugins.jetbrains.com/plugin/26480-kotlin-external-fir-support?noRedirect=true">Marketplace</a>.
+    </note>
+</topic>

docs/pages/kotlinx-rpc/topics/plugins.topic

@@ -7,7 +7,7 @@
         SYSTEM "https://resources.jetbrains.com/writerside/1.0/xhtml-entities.dtd">
 <topic xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
        xsi:noNamespaceSchemaLocation="https://resources.jetbrains.com/writerside/1.0/topic.v2.xsd"
-       title="Plugins" id="plugins">
+       title="Gradle plugin" id="plugins">
     <p>
         The <code>kotlinx.rpc</code> library offers a <a href="https://docs.gradle.org/current/userguide/plugins.html">Gradle plugin</a>
         that simplifies project configuration by automating repetitive tasks: `org.jetbrains.kotlinx.rpc.plugin`