add `/ipfs/0.1.0` to protocols page

[DougAnderson444]

I see the subject protocol used in the code (like here https://github.com/libp2p/universal-connectivity/issues/66), but didn't find an explanation in the docs (so far, perhaps I missed it).

Would be great if there was an addition to this page:

https://docs.libp2p.io/concepts/fundamentals/protocols/#core-libp2p-protocols

Also, is there a complete listing to all the protocol strings somewhere?

Does this just mean "use all protocols starting with /ipfs/**/** ?

[DougAnderson444]

According to https://github.com/libp2p/rust-libp2p/blob/c93f753018af3a63c07e38c09672e0e1e8f1a385/protocols/identify/src/behaviour.rs#L79-L81 at least, it's described for Identify as

/// Application-specific version of the protocol family used by the peer,
/// e.g. `ipfs/1.0.0` or `polkadot/1.0.0`.

I know I would benefit from some detail about "protocol families" and how they relate to the protocol children.

Thanks!

[MarcoPolo]

Not sure if this should go in the protocols page because this isn't a standalone protocol. This is an option in identify. The details are here: https://github.com/libp2p/specs/blob/master/identify/README.md#protocolversion

I agree this is a bit confusing.

[p-shahi]

ref: https://github.com/libp2p/go-libp2p/issues/2294

[2color]

Closing this issue, given that this is a protocol specific parameter. I also agree this is confusing, but this can likely just be resolved with a comment in the rust-libp2p implementation indicating that it's purely metadata.