Rollup merge of #28289 - shepmaster:include_bytes-docs, r=alexcrichton
Rollup merge of #28289 - shepmaster:include_bytes-docs, r=alexcrichton

This can be shown with the example code

```rust
fn main() {
    let () = include_bytes!("/etc/hosts");
}

Which will have the error:

expected `&[u8; 195]`,
    found `()`

GBGamer/rust,GBGamer/rust,aidancully/rust,aidancully/rust,graydon/rust,aidancully/rust,aidancully/rust,GBGamer/rust,GBGamer/rust,GBGamer/rust,GBGamer/rust,aidancully/rust,GBGamer/rust,aidancully/rust,graydon/rust,graydon/rust,graydon/rust,graydon/rust,GBGamer/rust,graydon/rust