Describe every CSV that is required

[abelsiqueira]

Describe what CSV files (tabular data) are required. Some obvious candidates are the node metadata (capacity, investment costs, etc.), the edge metadata (capacity, investment costs, etc.), and the profiles (nodes and edges).

This is related to #100.

Document (where) for each CSV:

• Name of the csv
• Index (sets, e.g. assets or edges) for the file
• Name of the each column
• What is the type of each column
• What is the description of each column

Try to write everything using the most simple abstraction (just basic tables), but if that is not enough, consider looking into a schema.