Add SI/Include example topology files in SI (later)

[davidlmobley]

For after our first publication, we should include some example input files in our supporting information, as per #91 :

4/ Is that possible to include an example of the practical single/dual topology files as part of SI? As a GROMACS user I'm particularly interested in this. Maybe just for a transformation of benzene to benzyl alcohol as illustrated in Fig 3. The detailed parameters may not be necessary but it will be good to show the actual format differences between single and dual topologies. I think it will benefit people (at least GROMACS users) in learning how to perform these simulations in practice.

We concluded that this was best done after our initiial publication.