Update kdocs of sortByColumns

Author: koperagen

core/src/main/kotlin/org/jetbrains/kotlinx/dataframe/jupyter/KotlinNotebookPluginUtils.kt

@@ -73,6 +73,10 @@ public object KotlinNotebookPluginUtils {
     /**
      * Sorts a dataframe-like object by multiple columns.
      * If a column type is not comparable, sorting by string representation is applied instead.
+     * Sorts DataFrames by their size because looking at the smallest / biggest groups after groupBy is very popular.
+     *
+     * Returns "lazily materialized" dataframe, which means get, getRows, take operation must be applied to turn it to a valid sorted dataframe.
+     * "lazily materialized" - after sorting 1 million of rows and given the page size = 100, a dataframe with only 100 rows is created.
      *
      * @param dataFrameLike The dataframe-like object to sort.
      * @param columnPaths The list of columns to sort by. Each element in the list represents a column path