Update AWS screenshoots

[LSheneman]

The GUI changed again. Most of https://khmer-protocols.readthedocs.org/en/v0.8.4/amazon/index.html is out of date. They added in a place to launch a volume with it, but I think we should led with the basic instructions as is.

Later we can do an advanced edition to show all the "cool" extras like this, parallel processes, etc. On a first run it is helpful to go through the steps, as it shows people how all the dots connect.