Simple text alert when Riposte is usable.
Uses combat log parry events to trigger instead of action usable to allow for better functionality.
Text alert will remain visible for the duration of the Riposte window provided that Riposte is not already on CD.
If Riposte is on CD and an attack is parried the text alert will pop back up as soon as Riposte is off CD and there is still time remaining in the current Riposte window.