Add IDs to markdown H4+ when TOC is generated
Add IDs to markdown H4+ when TOC is generated

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