Describe the problem you are trying to solve

To have syntax highlighting in VSCode I currently create a custom file association in my settings:

    "files.associations": {
        "**/.cargo/config": "toml"
    },

I'd love to not have to do this!

Describe the solution you'd like

Could cargo accept .cargo/config.toml as a path for local configuration?

Notes

There are many alternatives available, like making the Rust editor plugins aware of this association. However, cargo's usage of TOML elsewhere is identified by the file extension (consistency), and this change would presumably improve ergonomics in other places that do syntax highlighting, not just in editors (availability).