MSHT Parton Distribution Functions

Here we provide the standalone interface code and LHAPDF grids for the MSHT20 LO, NLO, NNLO and aN³LO PDFs described in arXiv:2012.04684, arXiv:2106.10289, arXix:2111.05357 and arXiv:2207.04739. These supersede the older MMHT14 PDFs (up to NNLO), described in arXiv:1412.3989.