Ad: SISAP'23 Indexing challenge

[maumueller]

Since ann-benchmarks is the meeting place for people working in approximate nearest neighbor search, I'd like to use the chance to advertise an indexing challenge that provides a different angle on ANN: https://sisap-challenges.github.io/ (Disclaimer: I provided some consultation on the challenge design)

All solutions that we benchmarked in ann-benchmarks (with fine-tuning for scale) should be eligible for the track A challenge, but track B and track C are concerned with finding binary embeddings and indexing these embeddings. I hope that some of you find this an interesting perspective and consider participating in the challenge.