Update packages/xo-server-perf-alert/.USAGE.md

Co-authored-by: Thomas Moraine <thomas.moraine@vates.tech>

packages/xo-server-perf-alert/.USAGE.md

@@ -5,6 +5,6 @@ You can define monitors in the plugin configuration. Monitors let you check stor
 
 Each monitored element gets its own alarm. The alarm triggers when an element goes over the defined threshold (based on the average over the last minute) and clears when it drops back below. An email alert is sent when an alarm is raised and when it clears. If there's an issue accessing the stats for a monitored element, an email will be sent too.
 
-To ensure that each alert email is only sent once, the boolean state of each alarm is stored with an ID, e.g. `host|memoryUsage|40|803c2676-c309-721e-7123-e6c3de854c32` is the ID corresponding to the alarm that is raised when host `803c2676-c309-721e-7123-e6c3de854c32` exceeds 40% memory usage.
+To avoid sending duplicate alerts, each alarm's boolean state is stored with a unique ID. For example, `|host|memoryUsage|40|803c2676-c309-721e-7123-e6c3de854c32` represents an alarm triggered when host `803c2676-c309-721e-7123-e6c3de854c32` exceeds 40% memory usage.
 
 You can use the "Test plugin" option to receive an email containing the list of the monitors you have configured, and the status of the elements monitored.