Update docs/topics/whatsnew1620.md
Update docs/topics/whatsnew1620.md

Co-authored-by: Danil Pavlov <98f29eee37c39b3a019d8dedeedaecafa583978b@jetbrains.com>
JetBrains/kotlin-web-site,hltj/kotlin-web-site-cn,JetBrains/kotlin-web-site,JetBrains/kotlin-web-site,hltj/kotlin-web-site-cn,JetBrains/kotlin-web-site,hltj/kotlin-web-site-cn,JetBrains/kotlin-web-site,hltj/kotlin-web-site-cn,JetBrains/kotlin-web-site,hltj/kotlin-web-site-cn,hltj/kotlin-web-site-cn