root/pypi: links for spire-xls-free

root/pypi Spire.Xls.Free-14.12.4-py3-none-win_amd64.whl
root/pypi Spire.Xls.Free-14.12.4-py3-none-manylinux1_x86_64.whl
root/pypi Spire.Xls.Free-14.12.4-py3-none-macosx_10_7_universal.whl