Update forum topic structure docs with intended poll additions
Update forum topic structure docs with intended poll additions

notbakaneko/osu-web,notbakaneko/osu-web,nanaya/osu-web,ppy/osu-web,LiquidPL/osu-web,LiquidPL/osu-web,nanaya/osu-web,notbakaneko/osu-web,LiquidPL/osu-web,LiquidPL/osu-web,notbakaneko/osu-web,ppy/osu-web,ppy/osu-web,nanaya/osu-web,nanaya/osu-web,ppy/osu-web,nanaya/osu-web,notbakaneko/osu-web,ppy/osu-web,LiquidPL/osu-web