More advanced examples are needed

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Users have requested that examples are provided that showcase more advanced features of MUSE.

From Andelka: It would be very useful if the templates were expanded to include also some representations
of the more advanced concepts, particularly related to the main principle, which is agent-based modelling. Examples going over the different attributes of agents, more complex
objectives, search rules, budget, agent population and interactions would be very useful.

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Add at least 2 further model examples need to be created, and document them in the "Customising MUSE Tutorials" section:

1) Demonstrates different decision rules (weighted sum and epsilon constraint - the latter should use an economic objective first and then refine based on environmental performance) and budget limit
2) Demonstrates agent interaction

And alter the Add an Agent example to demonstrate agent population and give one agent a very different objective and decision rule.

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