loongson/mirror: links for f-cell

loongson/mirror f_cell-0.3.20.0.tar.gz
loongson/mirror f_cell-0.3.20.0-py3-none-any.whl
loongson/mirror f_cell-0.3.7.tar.gz
loongson/mirror f_cell-0.3.7-py3-none-any.whl