Instructions about nogui should note that sims cannot be run nogui without modification

[StephenJRead]

Given that the various web pages encourage people to use some of the sims as potential starting points for projects, it would be good to explicitly note that while the ra25 project can be run nogui, the sims cannot because they lack the necessary code.

In hindsight it is obvious, but the ability to run nogui is not a general characteristics of an emergent program, but instead requires something like the specific code found in the ra25 project.