docs: update link to redis install guide (@fehmer) (monkeytypegame#6984)

fixes monkeytypegame#6983

Author: fehmer

docs/CONTRIBUTING_ADVANCED.md

@@ -111,7 +111,7 @@ Follow these steps if you want to work on anything involving the database/accoun
 
 | Manual                                                                                                                                                                                                                            | Docker (recommended)                                                                                                                                                        |
 | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
-| <ol><li>Install [MongoDB Community Edition](https://docs.mongodb.com/manual/administration/install-community/)</li><li>Install [Redis](https://redis.io/docs/install/install-redis/)</li><li>Make sure both are running</li></ol> | <ol><li>Install [Docker](http://www.docker.io/gettingstarted/#h_installation) on your machine</li><li>Run `npm run docker-db-only` from the `./backend` directory</li></ol> |
+| <ol><li>Install [MongoDB Community Edition](https://docs.mongodb.com/manual/administration/install-community/)</li><li>Install [Redis](https://redis.io/docs/latest/operate/oss_and_stack/install/install-stack/)</li><li>Make sure both are running</li></ol> | <ol><li>Install [Docker](http://www.docker.io/gettingstarted/#h_installation) on your machine</li><li>Run `npm run docker-db-only` from the `./backend` directory</li></ol> |
 
 3. (Optional) Install [MongoDB-compass](https://www.mongodb.com/try/download/compass?tck=docs_compass). This tool can be used to see and manipulate your database visually.
    - To connect, type `mongodb://localhost:27017` in the connection string box and press connect. The Monkeytype database will be created and shown after the server is started.