v0.2

• New feature: Scalar Quantization with 8 bits on PDX+ADSampling. We calculate distances in 8-bits (symmetric calculations) instead of decoding to floats.
• New algorithm: IVF₂, A Two-level IVF index that reduces the time to find the nearest centroids in larger collections. Achieves extremely high throughputs when paired with SQ8. Check some benchmarks here.
• Improvements to the PDX data layout to tackle the poor performance gains when K > 10. Read more here. This new layout substantially reduce I/O on the PRUNE phase of the algorithm.
• Added new datasets from the VIBE benchmark.
• Created a playground to test the raw performance of PDX vs SIMD kernels.
• Removing unnecessary code from SIGMOD experiments.
• Added MIT LICENCE.
• Improved README.
• Improved examples.