add update-errors target to recreate zip_errors.mdoc from zip.h
add update-errors target to recreate zip_errors.mdoc from zip.h

det/libzip,cysp/libzip,JanX2/libzip-git,det/libzip,cysp/libzip,det/libzip,projedi/libzip,cysp/libzip,JanX2/libzip-git,projedi/libzip,projedi/libzip,projedi/libzip,cysp/libzip,det/libzip