Dockerize the Richie documentation & website

[mbenadda]

Feature Request

Is your feature request related to a problem or unsupported use case? Please describe. The documentation website for Richie uses yarn for local development and build. This is fine for frontend developers but might be a problem for developers who prefer to operate everything inside containers.

It also means users need to use yarn if they wish to see the documentation website locally (as opposed to the published online version).

Describe the solution you'd like A new entry can be added in docker-compose to allow (at least) yarn start which serves the docs website, and could go further to allow work on the docs (with eg. yarn version)/

Describe alternatives you've considered N/A

Discovery, Documentation, Adoption, Migration Strategy We can then add a line in the main README.md that points to the way the docs website can be served locally.

Do you want to work on it through a Pull Request? 🚪🏃‍♂️

[mbenadda]

This work should also encompass Makefile tasks related to the docs website, as well as one for to run prettier on it, just like we have for the frontend.