Introduce Code Owners

[jlprat]

What is currently missing?

As a contributor, I want to have a speedy review process.
As a maintainer, I want to be notified and have PRs assigned to me when a person contributes a change in the area of the codebase I take care of.

How could this be improved?

Using the code owners feature from GitHub (https://docs.github.com/en/repositories/managing-your-repositorys-settings-and-features/customizing-your-repository/about-code-owners)

Is this a feature you would work on yourself?

• I plan to open a pull request for this feature