Add indicators on projects, regarding the available designs issues and the design tags found

[ifeneris]

Based on a technical solution we are looking for at #60, this issue is about providing indicators of available (open) design issues for each project, both on the "projects" page (in each project) and on each project page. Apart from numeric indicators, we can also show the names of the design tags we found on them, including the "good first issue" tag (if that concerns design tasks).

This way, visitors may quickly identify which projects have open design needs, how many, and what kind.

[fivenp]

If you look at the examples we refer to for quickstarts (this is what we tell projects to do) - there are some suggestions on how to structure the internal workflows and issue management.

We should def. also adapt them – or get inspired by those guides.....