Added documentation on adapting Persephone

Manifest.toml

Project.toml

docs/build/adapting.html

docs/build/architecture.html

docs/build/assets/architecture.png

docs/build/assets/architecture.svg

docs/build/assets/model_object.png

docs/build/assets/model_object.svg

docs/build/crops.html

docs/build/developing.html

docs/build/farm.html

docs/build/gis.html

docs/build/index.html

docs/build/io.html

docs/build/nature.html

docs/build/odd.html

docs/build/search.html

docs/build/search_index.js

docs/build/simulation.html

docs/build/species-dsl.html