Handle Twitch clip embeds

Twitch clips currently embed poorly, only showing the title, description, and thumbnail.

Include the video in the embed.

Another popular chat platform embeds them in a playable state. I'm not sure what special handling the other chat platform uses, or if Twitch handles requests from the platform uniquely. Example link if needed: https://www.twitch.tv/bobbybigballz19/clip/ArtsyAcceptableBurritoTheRinger-EPuo4Ha_SNQK_m5Q