doc docx pdf ppt pptx xlsx csv xls 这些所有文件类型的 mimetype

分别为：

• .doc: application/msword
• .docx: application/vnd.openxmlformats-officedocument.wordprocessingml.document
• .pdf: application/pdf
• .ppt: application/vnd.ms-powerpoint
• .pptx: application/vnd.openxmlformats-officedocument.presentationml.presentation
• .xlsx: application/vnd.openxmlformats-officedocument.spreadsheetml.sheet
• .csv: text/csv
• .xls: application/vnd.ms-excel