Link to private item warning irrelevant in binary crates

[Ploppz]

I get this warning in my binary crate

warning: public documentation for `Poller` links to private item `Poller::revive_dead_jobs`
  --> src/periodic_tasks/poller.rs:48:12
   |
48 | /// Next, [Poller::revive_dead_jobs] is called, which compares jobs registered in the database with
   |            ^^^^^^^^^^^^^^^^^^^^^^^^ this item is private
   |
   = note: this link resolves only because you passed `--document-private-items`, but will break without

However, cargo doc by defaults actually documents private items (which I find perfectly reasonable, as this documentation is specifically for other developers to understand the internals).

My suggestion is that binary crates should default to #![allow(rustdoc::private_intra_doc_links)].

[jyn514]

@Ploppz rustdoc doesn't document private items for binaries by default, cargo passes it --document-private-items. I think this should be reported upstream to cargo, which can pass it -Arustdoc::private-intra-doc-links at the same time.