Add secrethitler.io

[laggycomputer]

Checklist

• [x] I'm reporting a feature request
• [x] I've checked for similar feature requests including closed ones

Description

I propose the addition of the site SecretHitler.io, an online platform for the Secret Hitler social deduction game. I'm not sure how their web platform works but it is open source (not sure how up to date the repo is). Here is a valid profile: https://secrethitler.io/game/#/profile/lemmie

[ppfeister]

SecretHitler is behind Cloudflare, meaning normal queries will be blocked.

This can be added, but only after both #2069 and #2079 are merged. Assuming they both actually get merged, it will still only be functional when using a FlareSolverr proxy -- not when running standalone.