v0.4.0

New

• to_gpu and to_cpu methods were brought back, but without consuming the original index. Unlike in into_gpu, both indexes can be used separately and are independent from each other.
• Added slicker FlatIndex::new_l2 and FlatIndex::new_ip constructors.
• FlatIndex is now reachable at the crate's root.

Breaking Change

• GpuIndexImpl::from_cpu is no longer in the public API (its use was already ill advised).
• Invalid description input to index_factory will return a new error variant instead of panicking.

Fixes

• Documentation on indexes and GPU support was significantly improved.