fix: example in classes.md (#1873)
fix: example in classes.md (#1873)

* Update classes.md

* Update classes.md

Fixing typo
hltj/kotlin-web-site-cn,hltj/kotlin-web-site-cn,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,JetBrains/kotlin-web-site,JetBrains/kotlin-web-site,JetBrains/kotlin-web-site,JetBrains/kotlin-web-site