feat: add What's new in Kotlin 2.1.0 (#4574)

* feat: Guard conditions in when expressions (#4417)

* Guard conditions in when expressions

This PR adds information about Guard conditions in when expressions and how to use them.

* Alejandro's review

* chore: adding `is` in a branch

Co-authored-by: Alejandro Serrano <trupill@gmail.com>

* chore: adding `data` in code line

Co-authored-by: Alejandro Serrano <trupill@gmail.com>

* Andrey review

* Update docs/topics/control-flow.md

Co-authored-by: Andrey Polyakov <koshachy@gmail.com>

* chore: fix code comments

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Co-authored-by: Alejandro Serrano <trupill@gmail.com>
Co-authored-by: Andrey Polyakov <koshachy@gmail.com>

* feat: add What's new in Kotlin 2.1.0

* update: update WN in Kotlin 2.1.0

* fix: rollback style changed

* fix: style fixes

* update: some doc updates

* fix: apply patch

* Revert "feat: Guard conditions in when expressions (#4417)"

This reverts commit b778f28.

* fix: fix the link

* fix: deliver fixes

* fix: deliver fixes after review

* fix: deliver fixes after review

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Co-authored-by: alejandrapedroza <39709865+AlejandraPedroza@users.noreply.github.com>
Co-authored-by: Alejandro Serrano <trupill@gmail.com>

Author: 3 people

docs/topics/wasm/wasm-js-interop.md

@@ -399,7 +399,7 @@ You can use Kotlin `try-catch` expression to catch JavaScript exceptions.
 However, accessing specific details about the thrown value in Kotlin/Wasm isn’t possible by default.
 
 You can configure the `JsException` type to include the original error message and stack trace from JavaScript.
-To do so, add the following compiler flag to your `build.gradle.kts` file:
+To do so, add the following compiler option to your `build.gradle.kts` file:
 
 ```kotlin
 kotlin {
@@ -443,8 +443,8 @@ fun main() {
 }
 ```
 
-With the `-Xwasm-attach-js-exception` flag enabled, the `JsException` type provides specific details from the JavaScript error.
-Without the flag, `JsException` includes only a generic message stating that an exception was thrown while running JavaScript code.
+With the `-Xwasm-attach-js-exception` compiler option enabled, the `JsException` type provides specific details from the JavaScript error.
+Without enabling this compiler option, `JsException` includes only a generic message stating that an exception was thrown while running JavaScript code.
 
 If you try to use a JavaScript `try-catch` expression to catch Kotlin/Wasm exceptions, it looks like a
 generic `WebAssembly.Exception` without directly accessible messages and data.