[FEATURE] Improved resource (and general) linkchecking

[VeckoTheGecko]

Describe your suggested improvement
Currently, linkchecking for resources is done by a bespoke script, which works well and fails runs that have broken links.

Looking into linkchecking in general, I think that there is room for use of tools like Lychee to run linkchecking on the whole codebase (in fact, the example action they have also automagically creates issues in the codebase for broken links, which would be super neat for surfacing these issues).

Describe the benefit
Working links and resources = happy users

Would you be capable/willing to implement the improvement?
Likely yes

Additional comments
Currenlty in the brainstorming/exploration phase. Please discuss before submitting a PR.