fix(rust): handle destructured params case (#617)

[kkoomen]

Fixes #617

[RasmusRendal]

In some cases, it just seems to ignore arguments?

pub struct SorryForBeingMean {
    pub x: i8,
    pub y: i8,
}

pub fn some_function(SorryForBeingMean {x, y}: SorryForBeingMean) -> i8 {
    x * y
}

pub struct SorryForBeingMean (i8, i8);

pub fn some_function(SorryForBeingMean (x, y): SorryForBeingMean) -> i8 {
    x * y
}

You can do crazy things with these arguments, and I'm not even sure what the correct way to write rustdocs for these things are, so I totally understand if you don't want to support everything. For reference, this was the pattern I was trying to document: https://docs.rs/actix-web/latest/actix_web/web/struct.Form.html#examples

Thanks for the good work! ❤️

[kkoomen]

Mhm, there doesn't seem to be anything specific indeed about how to write it. I'll just keep it like this for now and when rustdoc will be more mature, I'll just receive some PRs about this at some point in time :)