Add .doc .ppt (Word and PowerPoint 97/2003 formats)

[Fabio3rs]

To avoid manually converting documents saved in old format, add for the loader to load these as well

[mdeweerd]

Thanks for adding those - I was not sure that these filters work for doc/ppt as well.

I tried to keep the lists in alphabetical order - doc is before docx, and ppt before pptx. It will avoid future false identifications of changes if someone decides to sort them.

[Fabio3rs]

Thanks for adding those - I was not sure that these filters work for doc/ppt as well.

I tried to keep the lists in alphabetical order - doc is before docx, and ppt before pptx. It will avoid future false identifications of changes if someone decides to sort them.

Thanks, I changed the order.

Seems to work fine here with the version in the requirements.txt, apparently the library converts the files into docx/pptx in background to use it.