Hi @ikeda-minden - Yeah, the substrate.io doc’s are out of date, although there is work being done as we speak to ensure all doc’s are given a thorough update (and maintained), so this is currently a WIP.
The teams behind it are Parity, W3F & the Papermoon Team who we’re recently awarded funds for their DF Proposal.
You can check out their original DF Futures Proposal here: Decentralized Futures: Ecosystem DevRel Team for Polkadot by PaperMoon