Provide mutations numbers corresponding to pp1ab for ORF1b

[EmilyHaag]

User suggestion: "Since ORF1b does exist, but isn’t translated, I might suggest that on your website, when you provide the mutation #s for ORF1b, that you instead refer to mutations numbers as they correspond to pp1ab. This would provide clarity and be more in line with the rest of the field."

The user sent a help email asking for the translated sequence we are using for the ORF1b mutation sites because 'since ORF1b isn’t translated into a discriminate protein, [she was] having a very difficult time mapping the mutations provided in the lineage a report to the pp1ab sequence.'