Add possibility to extend, reuse, load shareable organisation-wide configuration

[xeho91]

I am wondering if anyone else feel the need an ability of having a shared configuration for several repositories?

---

Inspiration

Similarly to what ESLint (from the JavaScript ecosystem) has: https://eslint.org/docs/latest/extend/ways-to-extend#shareable-configs

However, the difference would be, that instead of providing an organisation name, as ESLint allows to do so, like:

{
   "extend": "@org-name"
}

Which is a Node.js package uploaded to registry (either public - npmjs.com, or other).

---

Possible solution

In the case of Rust ecosystem, I believe the most convenient way would be providing a whole URL link to the .rustfmt.toml file hosted on any repository hosting service like GitHub.

Example:

extend = "https://github.com/xeho91/rust-tools/blob/main/.rustfmt.toml"

What about private/secured access?

The only concern I have for now, what if the repository is private?
I guess, we could do similarly to what Cargo.toml does with using ssh://git@github.com/....