Added developper's guide with introduction
Added data structure file with introduction
Added basic Nutrient model
Simplified the datamodel for nutrients
Added cli to create and list nutrients
Added flag to initialize the DB
Implemented Listing of nutrients
Added definitions for ingredients and the nutrient ingredients mappings
Fixed wrong table names in ingredients nutriments mapping
Fixed wrong names in ingredient model constructor
Expanded CLI to add and list nutrients
renamed action add to new
Fixed typo in IngredientNutriment table
Now allow to add nutrients to an ingredient
woops, forgot it
Added the command to show the nutrients (only ID for the moment)
Now show the actual nutrient name in show nutrient
fixed typo
Added proxy to nutrients
made the ingredient_nutrients a dictionary