Enhance document on simple ase examples

[alchem0x2A]

@ltimmerman3 I added more examples on the simple examples in the documentation and the doc should be more or less in shape.

Please help me check a few things:

1. I reformatted your examples doc into separate files (shown as individual pages), please check if they make sense
2. There is still a file env.sh in the examples folder, which I believe is for setting up in PACE. If all the examples can be run locally, we could remove that

[ltimmerman3]

Minor typo in basic usage.

# Using GPAW
from gpaw import GPAW
calc = GPAW(xc="PBE", kpts=(9, 9, 9), h=0.25, directory="vasp-calc", convergence={"energy": 1.e-4})

directory should be "gpaw-calc"

[ltimmerman3]

If you could add the requested note to the plumed example, I think these are good to go

[ltimmerman3]

Can you add a note that PLUMED must be downloaded and compiled separately. Also, the environment variable PLUMED_KERNEL must be set to the location of the libplumedKernel.so

[ltimmerman3]

Also need py-plumed installed, but this can be done via conda-forge or pip

[ltimmerman3]

Also adding the magmom and magmoms to implemented properties should be done. Currently only available when a .static file is generated (all socket calcs, singlepoints with forces etc.)