advertise a broader scope of what SST can be used for

[bhpayne]

On the page https://sst-simulator.org/ the tagline is "Using the supercomputers of today to build the supercomputers of tomorrow." That's the majority use case of SST (based on the user community meeting earlier this week), but a PDES framework can be used for other efforts. One I learned of at the user community meeting is for autonomous systems.

If the scope of SST is limited to just simulation of HPC that would be useful to make explicit.