loongson/pypi: links for headless-pdfkit

loongson/mirror headless_pdfkit-0.1.5.tar.gz
loongson/mirror headless_pdfkit-0.1.4.tar.gz
loongson/mirror headless_pdfkit-0.1.3.tar.gz
loongson/mirror headless_pdfkit-0.1.2.tar.gz
loongson/mirror headless_pdfkit-0.1.1.tar.gz
loongson/mirror headless_pdfkit-0.1.tar.gz