docs(rust): add note about cargo update fix in Rust quickstart

[amoeba]

Ref #3687

[lidavidm]

I'd worry we have to update this every time we release; also, can we link to upstream docs on the issue?

[amoeba]

I updated the command so it will work for the released docs as @eitsupi suggested.

I went looking for a good, single link and didn't find anything I liked. But I did update the text a bit and add a link to the cargo book which talks about this a bit. See c402638.

Here's what this looks like now:

[lidavidm]

@mbrobbel does this look reasonable?