README: Update notable users

[jxs]

Updated and sorted the list with names of the projects and oficial description instead of just the url. Removed the ones which don't seem to be using rust-libp2p anymore and added new users.

Removed:

• https://github.com/paritytech/polkadot (couldn't find direct usages of rust-libp2p on the code)
• https://github.com/golemfactory/golem-libp2p (isn't updated since May 2019, couldn't find usage of nor golem-libp2p nor rust-libp2p on their new implementation yagna)
• https://github.com/marcopoloprotocol/marcopolo (no longer exists, and I couldn't find usage of rust-libp2p in the only Rust repo on the organization)
• https://www.actyx.com/developers/ (their github organization doesn't have any Rust repo)

Added:

• Iroh
• Locutus
• Subspace

Please feel free to correct if I erroneously removed any.

[thomaseizinger]

• paritytech/polkadot (couldn't find direct usages of rust-libp2p on the code)

Polkadot uses libp2p transitively through substrate but polkadot is probably the more known project. Not sure about this case :)

[jxs]

• paritytech/polkadot (couldn't find direct usages of rust-libp2p on the code)

Polkadot uses libp2p transitively through substrate but polkadot is probably the more known project. Not sure about this case :)

good point, my rationale was to try to link to the code usages of rust-libp2p. Context: the idea came from the community call, where tutorials were being discussed and someone mentioned that usages of rust-libp2p could also serve as examples. But your question makes sense, what if we refer Polkadot on the Substrate description?