Redis destination connector: add setup how-to video embed link (#478)

Author: Paul-Cornell

snippets/general-shared-text/redis.mdx

@@ -1,3 +1,13 @@
+<iframe
+width="560"
+height="315"
+src="https://www.youtube.com/embed/_zpzzr2VtoM"
+title="YouTube video player"
+frameborder="0"
+allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture"
+allowfullscreen
+></iframe>
+
 - A [Redis](https://redis.io) database, for example in [Redis Cloud](https://redis.io/cloud/).
 - The target database's hostname and port number. [Create a database in Redis Cloud](https://redis.io/docs/latest/operate/rc/rc-quickstart/#create-an-account).
 - The username and password for the target database. [Get the username and password in Redis Cloud](https://redis.io/docs/latest/operate/rc/rc-quickstart/#connect-to-a-database).