[asherkin]

The text on the site is correct, I think you may just be confused between SourceMod and Metamod:Source.

MM:S's VDF file is metamod.vdf, you download it from that page and it goes in /orangebox/tf/addons since it's a VSP (Valve Server Plugin).

SourceMod's VDF file is sourcemod.vdf, and it's included in the SourceMod download and goes in /orangebox/tf/addons/metamod since it's a Metamod:Source plugin.