Merge pull request #2609 from zhzy0077/patch-1

Remove the duplicated entry in sorted-sets.md

Author: dwdougherty

docs/data-types/sorted-sets.md

@@ -244,7 +244,3 @@ If you need to index and query your data, consider the [JSON](/docs/stack/json)
 
 * [Redis Sorted Sets Explained](https://www.youtube.com/watch?v=MUKlxdBQZ7g) is an entertaining introduction to sorted sets in Redis.
 * [Redis University's RU101](https://university.redis.com/courses/ru101/) explores Redis sorted sets in detail.
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-* [Redis Sorted Sets Explained](https://www.youtube.com/watch?v=MUKlxdBQZ7g) is an entertaining introduction to sorted sets in Redis.
-* [Redis University's RU101](https://university.redis.com/courses/ru101/) explores Redis sorted sets in detail.