Feature: "I find this review helpful"

[luciojb]

I looked for a way to vote in a review, aka find it helpful, and as i searched for issues here, i didn't find any concerning this feature. So, if there is how to do it in the mal api, then please add some kind of button in the review to find it helpful.

Thanks for your work in the app, i'm using it every time i update my lists.

[Drutol]

Hello, sounds pretty doable. I'll see to it ^^