We aren't directly putting more water vapor into the atmosphere, but a warmer atmosphere can hold more water and (I would think) would also increase the overall rate of evaporation.
Regarding the greenhouse effect of water vapor, I don't know whether what matters is the average relative humidity or the total amount of water vapor in the atmosphere. For our sake I hope it's the former.
Now, we could potentially make many more clouds. For instance, container ships could be required to have fuel additives or “salt lofters”that promote cloud seeding and marine cloud brightening.