add kotlin-playground styles to MULTYPLATFORM.md (#2080)
add kotlin-playground styles to MULTYPLATFORM.md (#2080)


JetBrains/kotlin-native,wiltonlazary/kotlin-native,JetBrains/kotlin-native,JetBrains/kotlin-native,wiltonlazary/kotlin-native,wiltonlazary/kotlin-native,JetBrains/kotlin-native,JetBrains/kotlin-native,wiltonlazary/kotlin-native,wiltonlazary/kotlin-native,JetBrains/kotlin-native,JetBrains/kotlin-native,JetBrains/kotlin-native,JetBrains/kotlin-native