[joss-reviews#2974] Class design regarding Moead and Problems

[chkoar]

Related: openjournals/joss-reviews#2974

Moead and Problem classes require files, but I cannot see their definition somewhere documented.

A better option could be to work directly with data structures. (arrays, lists, dicts)
Helper functions could be created in order to avoid the clutter of loading these.

[geoffreyp]

Hello, the documentation is updated to explain how to use and generate these files.
I explain the utility of instance files for problems in #16.

We choose to externalize the weight-vector component by using files because there are many ways to generate weight vectors for multi-objective optimization by decomposition and this way allow the researcher to use the same weight-vectors with different algorithms/framework. We provide some example files with the framework: https://github.com/moead-framework/data/blob/master/weights

[chkoar]

Let's keep only the #16