Features/setup new module structure

[jnnr]

• Fix error importing cartopy

TODO

Structure

• Setup general structure sketched in Module structure to be settled #14
  • Do consistency checks
  • Assert that required parameters are defined
  • Set default values
  • Models and results

Clean up

• Write docstrings
• Add module headers
• Render components and components_attrs in docs
• Check if examples are working
• Fix failing tests and linters
  • Fix error on installation when installing rtree