Added some info to the redis chapter

docs/redis.md

@@ -1,15 +1,22 @@
 ### Client
 
+Redis is used as a key-value store for (some of) mailcow's and rspamd's settings and data. If you are unfamilliar with redis please read the [introduction to redis](https://redis.io/topics/introduction) and maybe visit this [wonderfull guide](http://try.redis.io/) on how to use it.
+
+To connect to the redis cli execute:
+
 ```
 docker-compose exec redis-mailcow redis-cli
 ```
 
-## Remove persistent data
+Here are some usefull commands for debugging:
 
-- Remove volume `mysql-vol-1` to remove all MySQL data.
-- Remove volume `redis-vol-1` to remove all Redis data.
-- Remove volume `vmail-vol-1` to remove all contents of `/var/vmail` mounted to `dovecot-mailcow`.
-- Remove volume `dkim-vol-1` to remove all DKIM keys.
-- Remove volume `rspamd-vol-1` to remove all Rspamd data.
-
-Running `docker-compose down -v` will **destroy all mailcow: dockerized volumes** and delete any related containers.
+!!! info
+    - **monitor**: Listens for all requests received by the server in real time.
+    ```
+    # docker-compose exec redis-mailcow redis-cli
+    127.0.0.1:6379> monitor
+    OK
+    1494077286.401963 [0 172.22.1.253:41228] "SMEMBERS" "BAYES_SPAM_keys"
+    1494077288.292970 [0 172.22.1.253:41229] "SMEMBERS" "BAYES_SPAM_keys"
+    [...]
+    ```