feat: Mark down plugins script

[Rojikku]

Script that renames sites from check-plugin-sites.js to .broken versions.
Also adds options.down and options.downSince to multisrc files.

Obviously, you should manually verify the list of sites before running this script, as the previous script generates plenty of false positives.

Makes #1973 easier

[DVD-DAVIDE]

If the site check script left a timestamp on its report, and used simple versioning (like a .old file), we could try comparing the two to at least reduce the number of false positives.

P.S: actually, there already is a timestamp, so that should be simple to implement (maybe?).

Also, maybe we should consider taking into account why the site is broken, given the report also gives us a reason and status code.

[Rojikku]

Ah, so, when it comes down to it, I just use vscode and alt click all the links.
Then I erase the entry based on my judgement.
Takes maybe 5 seconds per entry.

Some didn't load, but looked like they might come back. Others seemed pretty dead.
Some loaded fine in a proper browser.
Some had region locks - obviously just kept those and figured it wasn't my problem.

Then the cloudflare ones are generally just good. If cloudflare is working, there's something there. I checked them all, but in retrospect, little point.

Didn't take that long. But you could totally compare it against an ignore list or something to ignore false positives, and between this (hopefully all) good update and that, it should be very minimal.
But then if an ignored one goes down, you don't know.

Could probably improve the detection, you're right, some of those errors probably indicate always good or always bad.
Would take some investigation into what they actually mean though. I don't have more energy today.

Those would actually be modifications to the other, existing, script, so you could probably do another PR making another section with stuff like "Denied but we know that means it exists" - though better naming required.

Another big thing I'd like to find is redirects. I know at least a couple plugins go to the same site now. Finding those and documenting them would probably be a productive addition.

Anyway, this just grabs one specific part of the json, so if you split that you control what's processed.

I also had the thought to make another script to open stuff in a web browser one and a time and let you tell it if they worked. Uncertain if that's difficult or worth the effort. Alt clicking wasn't hard.