[PROPOSAL] Additional Information for redis.io website

[Duong Nguyen]

When I was browsing the redis.io website, I stumbled upon this page:

https://redis.io/topics/whos-using-redis

And I found that the link to stackshare.io is not a complete list of the users of redis, so I found another link that is more complete:

https://siftery.com/redis

We can add this link to the page or just replace stackshare.io. Thought it would be a nice addition to the site.