Error converting .docx files with rel

[markfullmer]

As reported by @alekseynovikov78 , some .docx files will fail to convert, with the message:

There is no item named 'word/document.xml' in the archive.

We use the python library https://github.com/python-openxml/python-docx for .docx conversion. I haven't found an identical issue reported there, but a different library based on that one reports the exact issue, and a "bit of a hack" fix:

• docx created with word online ankushshah89/python-docx2txt#16
• https://github.com/ankushshah89/python-docx2txt/pulls/18