v2.1.37

• Add FullDuplexStream.CreatePipePair
• Add PrefixingBufferWriter<T> which implements IBufferWriter<T> with the ability to reserve space to fill in some header after writing the payload.
• Add Sequence<T>.MinimumSpanLength which prevents allocating many very small spans due to serializer patterns.
• Add Sequence<T>.ctor(ArrayPool<T>) for reduced GC compared to the MemoryPool<T> constructor.

See API diff since 2.0.228.