fix rebase issue

Author: koperagen

core/src/main/kotlin/org/jetbrains/kotlinx/dataframe/api/format.kt

@@ -16,6 +16,7 @@ import org.jetbrains.kotlinx.dataframe.io.DisplayConfiguration
 import org.jetbrains.kotlinx.dataframe.io.toHTML
 import org.jetbrains.kotlinx.dataframe.io.toStandaloneHTML
 import kotlin.reflect.KProperty
+import org.jetbrains.kotlinx.dataframe.io.DataFrameHtmlData
 
 // region DataFrame