update broken cockroachdb link (#7409)

Author: carlagn

content/200-orm/050-overview/500-databases/840-cockroachdb.mdx

@@ -90,7 +90,7 @@ model User {
 
 For compatibility with existing databases, you may sometimes still need to generate a fixed sequence of integer key values. In these cases, you can use Prisma ORM's inbuilt [`sequence()`](/orm/reference/prisma-schema-reference#sequence) function for CockroachDB. For a list of available options for the `sequence()` function, see our [reference documentation](/orm/reference/prisma-schema-reference#sequence).
 
-For more information on generating database keys, see CockroachDB's [Primary key best practices](https://www.cockroachlabs.com/docs/v21.2/schema-design-table#primary-key-best-practices) guide.
+For more information on generating database keys, see CockroachDB's [Primary key best practices](https://www.cockroachlabs.com/docs/stable/schema-design-table#select-primary-key-columns) guide.
 
 ## Example