Installing AWS Palace in Singularity/Apptainer container

Instructions to build palace as a Singularity/Apptainer container are given here. By default, this setup builds the latest commit of awslabs/palace on main with OpenMP support (no GPU).

To use these containers for simulations, set the palace-dir user option to point to the palace.sif file (or whatever you named your container).

TODO: Properly verify this…