Create a Portal for Symmetric Discrete Objects

[tkw1536]

@katjabercic suggested we might want to aim for creating a portal of discrete mathematical objects and use them as a driver to extend the platform.

There are a few collections of objects that are closely related:

• CVT
• Graphs
• Maps embedded onto the plane

[katjabercic]

• This may make sense to do via the Ljubljana MDH instance.
• The first dataset to add: A Census of edge-transitive tetravalent graphs by Steve Wilson and Primož Potočnik (partially parsed by @tkw1536 )