Log message:
tex-uptex{,-doc}: Add version 2020

From Atsushi Toyokura in pkgsrc-wip

upTeX is an extension of pTeX, using UTF-8 input and producing
UTF-8 output. It was originally designed to improve support for
Japanese, but is also useful for documents in Chinese and
Korean. It can process Chinese simplified, Chinese traditional,
Japanese, and Korean simultaneously, and can also process
original LaTeX with \inputenc{utf8} and Babel
(Latin/Cyrillic/Greek etc.) by switching its \kcatcode tables.