Allowing multiple independent input data sets

[AugustT]

@drnickisaac is going to think long and hard about how we can allow multiple input data sets

"clearly this is a tricky one"

special cases:

• non-overlapping species
• non-overlapping time periods

@FrancescaMancini

• [ ] Create a plan for how these can be integrated
• [ ] Create a new issue which outlines the changes needed to implement the plan