"datastore.upload_files" is deprecated after version 1.0.69

In `azureml-core 1.37.0.post1`, we have gotten the warning message like the below:
```
"datastore.upload_files" is deprecated after version 1.0.69. Please use "FileDatasetFactory.upload_directory" instead. See Dataset API change notice at https://aka.ms/dataset-deprecation.
```

It seems that the URL points to [this page](https://github.com/Azure/MachineLearningNotebooks/blob/b05ff80e9dfc3d1a38031e9e701ebed841760463/how-to-use-azureml/work-with-data/dataset-api-change-notice.md), but there is no information for migration.

`datastore.upload_files` could specify files as a list explicitly even if the directory contains the file we don't want to upload like credential data, the file which contains personal data before processing, and so on.

How to use `FileDatasetFactory.upload_directory` as same as `datastore.upload_files`?

從 issue 中連結的 dataset API 變更通知，以及 Azure ML 關於 datastore.upload_files 和 FileDatasetFactory.upload_directory 的文件開始。記錄僅需上傳選取檔案時的遷移方式，包括相關的 API 選項和一個簡潔的範例。當通知說明等效的工作流程並處理遭排除的檔案時，即視為完成。

由索引模型根據 Issue 內容生成。