update: add Kotlin plugin contributing info (JetBrains#2687)

* update: add Kotlin plugin contributing info

* fix: fixes after review

* fix: small addition

Author: koshachy

docs/topics/contribute.md

@@ -10,21 +10,30 @@ You can help us improve Kotlin by [participating in Kotlin Early Access Preview
 For every release, Kotlin ships a few preview builds where you can try out the latest features before they go to production. You can report any bugs you find to our issue tracker [YouTrack](https://kotl.in/issue) 
 and we will try to fix them before a final release. This way, you can get bug fixes earlier than the standard Kotlin release cycle.
 
-## Contribute to the compiler, standard library, and tooling
+## Contribute to the compiler and standard library
 
-If you want to contribute to the Kotlin compiler, standard library, or tooling, go to [GitHub](https://github.com/jetbrains/kotlin), check out the latest Kotlin version,
+If you want to contribute to the Kotlin compiler and standard library, go to [JetBrains/Kotlin GitHub](https://github.com/jetbrains/kotlin), check out the latest Kotlin version,
  and follow [the instructions on how to contribute](https://github.com/JetBrains/kotlin/blob/master/docs/contributing.md).
- 
+
 You can help us by completing [open tasks](https://youtrack.jetbrains.com/issues/KT?q=tag:%20%7BUp%20For%20Grabs%7D%20and%20State:%20Open). 
 Please keep an open line of communication with us because we may have questions and comments on your changes. Otherwise, we won't be able to incorporate your contributions.
 
-## Contribute to other libraries and create your own
+## Contribute to the Kotlin IDE plugin
+
+Kotlin IDE plugin is a part of the [IntelliJ IDEA repository](https://github.com/JetBrains/intellij-community/tree/master/plugins/kotlin).
+
+To contribute to the Kotlin IDE plugin, clone the [IntelliJ IDEA repository](https://github.com/JetBrains/intellij-community/) and follow the [instructions on how to contribute](https://github.com/JetBrains/intellij-community/blob/master/plugins/kotlin/CONTRIBUTING.md).
+
+## Contribute to other Kotlin libraries and tools
 
 Besides the standard library that provides core capabilities, Kotlin has a number of additional (kotlinx) libraries that extend its functionality. 
 Each kotlinx library is developed in a separate repository, has its own versioning and release cycle.
 
-If you want to contribute to a kotlinx library, follow the contribution process described for each library, such as [kotlinx.coroutines](https://github.com/Kotlin/kotlinx.coroutines),
- [kotlinx.serialization](https://github.com/Kotlin/kotlinx.serialization/blob/master/CONTRIBUTING.md), and [ktor](https://github.com/ktorio/ktor/blob/master/CONTRIBUTING.md).
+If you want to contribute to a kotlinx library (such as [kotlinx.coroutines](https://github.com/Kotlin/kotlinx.coroutines) or
+[kotlinx.serialization](https://github.com/Kotlin/kotlinx.serialization)) and tools, go to [Kotlin GitHub](https://github.com/Kotlin), choose the repository you are interested in and clone it.
+
+Follow the contribution process described for each library and tool, such as
+[kotlinx.serialization](https://github.com/Kotlin/kotlinx.serialization/blob/master/CONTRIBUTING.md), [ktor](https://github.com/ktorio/ktor/blob/master/CONTRIBUTING.md) and others.
 
 If you have a library that could be useful to other Kotlin developers, let us know via <[email protected]>.
 
@@ -51,5 +60,4 @@ is correct and up to date. Unfortunately, we won't be able to review documentati
 
 ## Hold events and presentations
 
-If you've given or just plan to give presentations or hold events on Kotlin, please fill out [the form](https://surveys.jetbrains.com/s3/Submit-a-Kotlin-Talk). We'll feature them on [the event list](https://kotlinlang.org/docs/events.html).
-
+If you've given or just plan to give presentations or hold events on Kotlin, please fill out [the form](https://surveys.jetbrains.com/s3/Submit-a-Kotlin-Talk). We'll feature them on [the event list](https://kotlinlang.org/docs/events.html).