Replace maven repostiory sites (#3685)

* Replace search.maven.org with central.sonatype.com
* Replace mvnrepository.com by central.sonatype.com

Author: DRSchlaubi

README.md

@@ -3,7 +3,7 @@
 [![Kotlin Stable](https://kotl.in/badges/stable.svg)](https://kotlinlang.org/docs/components-stability.html)
 [![JetBrains official project](https://jb.gg/badges/official.svg)](https://confluence.jetbrains.com/display/ALL/JetBrains+on+GitHub)
 [![GitHub license](https://img.shields.io/badge/license-Apache%20License%202.0-blue.svg?style=flat)](https://www.apache.org/licenses/LICENSE-2.0)
-[![Download](https://img.shields.io/maven-central/v/org.jetbrains.kotlinx/kotlinx-coroutines-core/1.7.0-Beta)](https://search.maven.org/artifact/org.jetbrains.kotlinx/kotlinx-coroutines-core/1.7.0-Beta/pom)
+[![Download](https://img.shields.io/maven-central/v/org.jetbrains.kotlinx/kotlinx-coroutines-core/1.7.0-Beta)](https://central.sonatype.com/artifact/org.jetbrains.kotlinx/kotlinx-coroutines-core/1.7.0-Beta)
 [![Kotlin](https://img.shields.io/badge/kotlin-1.8.10-blue.svg?logo=kotlin)](http://kotlinlang.org)
 [![Slack channel](https://img.shields.io/badge/chat-slack-green.svg?logo=slack)](https://kotlinlang.slack.com/messages/coroutines/)
 
@@ -180,13 +180,13 @@ Platform-specific dependencies are recommended to be used only for non-multiplat
 #### JS
 
 Kotlin/JS version of `kotlinx.coroutines` is published as 
-[`kotlinx-coroutines-core-js`](https://search.maven.org/artifact/org.jetbrains.kotlinx/kotlinx-coroutines-core-js/1.7.0-Beta/jar)
+[`kotlinx-coroutines-core-js`](https://central.sonatype.com/artifact/org.jetbrains.kotlinx/kotlinx-coroutines-core-js/1.7.0-Beta)
 (follow the link to get the dependency declaration snippet) and as [`kotlinx-coroutines-core`](https://www.npmjs.com/package/kotlinx-coroutines-core) NPM package. 
 
 #### Native
 
 Kotlin/Native version of `kotlinx.coroutines` is published as 
-[`kotlinx-coroutines-core-$platform`](https://mvnrepository.com/search?q=kotlinx-coroutines-core-) where `$platform` is 
+[`kotlinx-coroutines-core-$platform`](https://central.sonatype.com/search?q=kotlinx-coroutines-core&namespace=org.jetbrains.kotlinx) where `$platform` is 
 the target Kotlin/Native platform. 
 Targets are provided in accordance with [official K/N target support](https://kotlinlang.org/docs/native-target-support.html).
 ## Building and Contributing