Convert a two-letter USA location abbreviation to a two-character USA location code
Source:R/recode_locations.R
us_loc_abbr_to_code.Rd
Given a vector of state/territory two-letter
USPS short names (e.g. MA, TX, PR), return
the corresponding location code typically used
in forecast hubs (legacy FIPS code for states and territories,
US
for the US).