0.13.0

What's Changed

• [topk-py][topk-js][topk-sql] group by by @petertoth in #512
• [topk-py][topk-js][topk-sql] add should() by @petertoth in #525
• [proto/rs] timestamp type and datetime ops by @marekgalovic in #526
• [es] track hits.total by @jerguslejko in #523
• [topk-sql] add keyword index type by @petertoth in #533
• [py/js] unknown proto variants by @jerguslejko in #534
• Release 0.13.0 & group by + offset docs by @petertoth in #524

Full Changelog: 0.12.1...0.13.0