[Feature request] support spesifying page number

[Aadniz]

Instead of only being able to do hentaifetch, and hentaifetch 236574, I'm requesting feature to spesify the page aswell.

Example like:

hentaifetch 236574/22

[quincynyan]

I will* implement it in the future in my fork, so stay tuned for that!

*Soon™