读取文本文件内容，新建目录，多级目录创建，新建文件，有编码方式的文件创建，删除文件，删除文件夹， 删除指定文件夹下所有文件-Read text file content, the new directory, multi-level directory to create new documents, the documents are encoded to create, delete files, delete the folder, delete the specified folder all documents