Add chapter to book for nightly use

[bioinformatist]

One may meet this problem when use Burn and another crate with hashbrown=^0.14 or earlier simultaneously.

Similar to rust-lang/hashbrown#564.

In our case, the older version of hashbrown is used by dashmap.

I've tried to add new feature flags to Burn, but it soon became a tedious business.

Another way is to add alias for older hashbrown like what the polars has done: https://github.com/pola-rs/polars/pull/19091/files, but I think it's not elegant enough as it can also be complicated.

So maybe the better way is to tell the users the solution in the book.

For more info: rust-lang/hashbrown#564 and zakarumych/allocator-api2#19.

[laggui]

Thanks for providing the steps and links!

I agree that having something like this documented is helpful for future reference, but I'm not sure we should add a nightly section to the book just for this.

Perhaps it could be left as an outstanding issue so users can easily refer to it? Open to suggestions.

[bioinformatist]

I'm not sure we should add a nightly section to the book just for this

I also feel something strange here 😅 since this issue may be solved by stable Rust in the future. Or let's move it to a pinned issue?

[laggui]

I also feel something strange here 😅 since this issue may be solved by stable Rust in the future. Or let's move it to a pinned issue?

A pinned issue for nightly stuff already makes more sense 😄

[laggui]

Closing as discussed. Feel free to open an issue with the description and solution.