Add aiType description

[red-tails]

From approx 2022-11 onwards, pixiv added an int aiType to the artwork search endpoint.

Seems that
aiType=0 is a backfill onto all old artworks
aiType=1 not specified as ai
aiType=2 specified as ai

This is self-reported and malicious artists can specify aiType=1 on ai-generated artworks.
https://www.pixiv.help/hc/en-us/articles/11866194231577

[daydreamer-json]

Now that I have been relieved from my busy schedule, OK, I will reflect this in the new version, which I will rewrite from scratch.
Sorry for the delay.