Resto Shaman dps is literally acid rain, which comes from healing rain, keep flame shock on at least 1 target and hit lava burst on cd and when flame shock proc resets it. That's 2 buttons since one is just a passive from your healing lol.
But nice try buddy, just because you have buttons doesn't make them optimal parts of the rotation. If you're using lightning bolt on a resto shaman you are doing it incredibly wrong.