Broken documentation and homepage link in Cargo.toml and email in CODE_OF_CONDUCT.md

[hola-kundan]

Hi, I noticed that the documentation and homepage fields in Cargo.toml currently point to http://immutable.rs, but this now shows a Caddy placeholder page rather than project docs.

Meanwhile, the README links to https://docs.rs/im/, which works fine and is probably what crates.io should point to.

Additionally, the contact email in CODE_OF_CONDUCT.md — admin@immutable.rs — may also be outdated given that the domain seems inactive.

Would it be okay if I submit a PR to:

• Update the Cargo.toml metadata to point to https://docs.rs/im/ and https://github.com/bodil/im-rs
• Suggest a more current contact instruction (e.g., open a GitHub issue)

Let me know. Thanks for maintaining this very useful crate!