Integrate `awesome-lint` CI to align with Awesome standards

[Frestein]

I'd like to propose adding awesome-lint CI. It's the official linter for Awesome lists, created by the maintainer of the main Awesome project.

Integrating it now will require a significant number of changes to the current README.md. However, this initial effort will be a major step forward.

Once the list is compliant, having awesome-lint in place will make it much easier to keep it that way. This, in turn, greatly simplifies any future work towards getting awesome-guix added to the official Awesome list, as a clean linter report is a key requirement for inclusion.

[franzos]

@Frestein great suggestion; I'll look into it one of these days.