DB2022 Adds new Rating

[fire-eggs]

The DB2022 database has added a new Rating value to the images table. The new rating is 'g'.

I say "new" because the 'g' rating doesn't exist in the DB2021 database [neither gwern's version NOR the BIGDATA version].

1. The browser needs to be updated to provide the new rating.
2. Need to know what the new rating represents.