document container files for SST

[researcherben]

SST is currently released as source code on https://github.com/sstsimulator/sst-core

Providing a container file ("Definition file" for Apptainer / Singularity, "Dockerfile" for Docker, "Containerfile" for Podman, etc) would help new users quickly run SST. For folks installing SST bare-metal, they would have clearly documented dependencies (compiler versions, library versions).

Apptainer Definition file examples for SST: https://github.com/tactcomplabs/sst-containers/tree/main/containers/singularity

[gvoskuilen]

Update: about ready to publish. Developing test for docker file. Also resolving issues with ARM-based mac & docker.