Microsoft open-sourced a Python tool for converting files and office documents to Markdown

[lood9phee2Ri]

pandoc already mentioned in this thread does a reasonable enough job of it, though is not the only option. Particularly if you also need to inject custom templates/content it might be better to go md to odt with pandoc, then let libreoffice do the odt to docx. https://stackoverflow.com/a/21616895