List of new features/elements:
* Added several scenarii that can be easily instantiated, similar to the
`make_basic_smartgrid` function.
* Added the `algorithms` module to the built package (published to pip).
* Improved documentation:
* Added a notebook example to show how to visualize rewards, and
compare algorithms.
* Added a short description of the pre-existing components in the
"API" page, to know what is available and access their documentation
faster.
* Added links to observations and rewards that support the moral
values, in the "Use case" page.
* Added contributing guidelines.
List of fixes:
* Fixed the Quick usage instructions, which would not work in a
"standard" Python shell (but correctly in an IPython shell).
* Fixed broken links in the Readme.