Add runnable `titanic` example

[MathisWellmann]

Changes include:

• Adds runnable (cargo run --example titanic) example
• Fix rs-example.md to include the third parameter to fit-unweighted
• Update dependencies where possible
• Format toml files with taplo fmt for consistency

[jinlow]

Thanks @MathisWellmann , this is great appreciate the addition of the example, and updates. Are there any more changes you were planning on adding with this PR? Otherwise I will approve and merge.

[MathisWellmann]

That would be all for now. Much appreciated :)