Add Redis stream trim example

Amolith created

Change summary

README.creole | 6 ++++++
1 file changed, 6 insertions(+)

Detailed changes

README.creole 🔗 

@@ -5,3 +5,9 @@ An XMPP to SMS gateway for Bandwidth's V2 Messaging API, using XEP-0100.  The "S
 Note that the canonical location for this repository is https://gitlab.com/soprani.ca/sgx-bwmsgsv2 .  Please use that location for all pull requests, issue reports, etc.  Other locations are likely out-of-date.
 
 This program expects a binary named "tai" to be in its working directory, which should be a compiled version of https://ossguy.com/tai.c for the platform it is running on.
+
+The gateway emits events to a Redis stream. To trim entries older than 7 days, put something like this in a cronjob:
+
+{{{
+redis-cli -u redis://127.0.0.1:6380/0 XTRIM stream MINID "~" "$(( ($(date +%s) - 7 * 24 * 60 * 60) * 1000 ))-0"
+}}}