Add GenDB to ClickBench

[alexey-milovidov]

Maybe it could grab the first place? https://github.com/ClickHouse/ClickBench/

[SolidLao]

Thanks so much for reaching out and suggesting we submit to ClickBench — we really appreciate it!

We're actively working on getting the benchmark set up and plan to submit our results in the future. Looking forward to seeing how we stack up against the other systems!

Best,
Jiale