Add ReductStore to database list

[atimin]

Hi there,

I'd be happy if you listed ReductStore.

Thanks!

For tracking:
reductstore/reductstore#1510

[vordimous]

Thanks @atimin — ReductStore is a solid, well-maintained project and a good fit. 👍

Two tiny style nits to match the rest of the list, then I will merge:

1. Capitalize the start of the description (high-performance → High-performance ...), since every other entry starts with a capital.
2. The added line introduces a trailing whitespace-only line before ## Data Comparison — could you make that a clean blank line (no spaces)?

Appreciate it!

[atimin]

Hi @vordimous, I've improved the style and formatting of my patch. Thank you!