A note about sktime.

Author: zhangxjohn

docs/en_US/source/contents/0200_installation.rst

@@ -80,3 +80,5 @@ or
     ValueError: In models with integration (d > 0) or seasonal integration (D > 0)...
 
 Please check the ``statsmodels`` version and control that it is not greater than 0.12.1.
+
+7. Since HyperTS version 0.2.3, ```hyperts``` has removed the dependency on ```sktime```, and ```sktime``` can be installed independently if you want to use the KNN algorithm in classification tasks.

docs/zh_CN/source/contents/0200_installation.rst

@@ -84,3 +84,5 @@ conda安装
     ValueError: In models with integration (d > 0) or seasonal integration (D > 0)...
 
 建议您检查 ``statsmodels`` 的版本并控制其版为0.12.1。
+
+7. 自HyperTS 0.2.3版本，hyperts移除了对sktime的依赖，如果在分类任务中想要使用KNN算法，可以独立安装```sktime```。