Fix nav link for jets documentation with docs.simplicity-lang.org

[iajhff]

I submitted updated docs for Jets to the documentation, this seems to be the best place to find an overview of Jets, and the Jets overview has more detailed information. Fixing this nav link. Thanks currently forwards to https://docs.rs/simplicityhl-as-rust where crate documentation doesn't exist. You may have meant https://docs.rs/simplicityhl/0.2.0/simplicityhl but this seems a more appropriate place

[apoelstra]

Oops -- we meant to link to https://docs.rs/simfony-as-rust/latest/simfony_as_rust/

We search-and-replaced the link but we need to rename and republish the crate.

[apoelstra]

Ah, the repo is renamed https://github.com/BlockstreamResearch/SimplicityHL-as-rust but we need to do a cargo publish. Ok.

[apoelstra]

BlockstreamResearch/SimplicityHL-as-rust#2 should fix this

[iajhff]

Ok thanks