if git sees the document type as an opaque thing, like various MS types, git diff is not a pleasant thing. i'm surprised someone hasn't made a differ for them for git. (Maybe they have, just haven't seen it).
The differ is `git diff`. If you insist on putting in binary files, it's not going to show you a textual diff. If you run `unzip` beforehand and put in the plain text contents of the ZIP (DOCX) instead of trying to put the ZIP in itself, then you'll get a textual diff.
