test: reorg fixtures in DescribeDocument
test: reorg fixtures in DescribeDocument

mohamedattahri/python-docx,python-openxml/python-docx,holli-holzer/python-docx,eruffaldi/python-docx,guilhermebr/python-docx,tanyunshi/python-docx,yurac/python-docx,Nuos/python-docx,SimplyAgree/python-docx,jean/python-docx