Forgive me if this is an old, long settled debate, but is there a designated space on a given game's main page to add links to TAS runs? I don't mean as a ranked leaderboard run, but as a resource / guide via external link to those who are interested?

Is there a designated place to post links to TAS runs or should I consider it a "guide" / "resource"?

Moderators can add a link to tas runs in guides/recourses. You should consider it that.

Expanding on what @Act7 said, you don't have to be a mod to add guides, so I recommend this route if you are not a mod.

You can also set the link from http://tasvideos.org/ as a community website for your game (if you are moderator).