I haven't personally added a suspension fork to a Como but I have made a Vado into a rigid front end. In the EU the Como can be equipped with Vado 700c wheels and front suspension, the components on the bikes are fairly interchangeable. For instance you can run 27.5 wheels on the Vado (which is what I do in the winter for studded tires) or you can put more road oriented 700c Vado wheels onto a Como (mind the fender clearance).
For suspension fork on Como, I believe it's a straight 1 1/8" steer, you'll want to note the steerer length of the stock fork, the axle-crown measurement, and offset (if you can). You'll want to keep things as close to stock as possible.
Worth noting, while you can decrease tire pressure for more comfort but you sacrafice effeciency, AKA range should that be a concern. By adding suspension you can keep the rider comfort and keep the rolling effeciency with a small weight penalty which can be negligible depending on where you're riding.