- add notebook that runs the plotting code
- add three visualizations per city:
+ all addresses, colored by zip code
+ all restaurants, incl. the number of received orders
+ all restaurants on a grid with pixel side length of 1000m
- add a Jupyter notebook that allows to install all project-external
dependencies regarding R and R packages
- adjust the GitHub Action workflow to also install R and the R packages
used within the project
- add a `init_r` module that initializes all R packages globally
once the `urban_meal_delivery` package is imported
- remove the factory functions for creating engines and sessions
- define global engine, connection, and session objects to be used
everywhere in the urban_meal_delivery package