Data file JSONS to use arrays / Creating CWW 2021 page

[KevinPayravi]

Several big changes and additions with this PR (feedback is more than welcome):

• Our member and affiliate JSONs are now arrays of objects. Main reason for this is that these are lists of like objects, so logically it makes sense to have them as arrays. Secondary reason is that it allows us to more easily access each wiki's ID, which has been moved from being the name of each object into an id property (and greedily for this PR, I use the ID to connect data objects between members.json and the new cww.json file).
• Creation of a new cww.json data file for Cross-Wiki Weekend, to make it easier to maintain each wiki's guides. The object contains arrays by year that list all members that are participating in CWW that year, along with the title and link to each member's Cross-Wiki Weekend guide. So far this only has data for 2021, but I'd like to eventually backport for previous years. Example of an object:

    {
      "id": "nookipedia",
      "title": "Cross-Wiki Guide",
      "link": "https://nookipedia.com/wiki/Nookipedia:Cross-Wiki_Weekend"
    }

• Creation of the CWW 2021 page. Looks similar to last year, but with some improvements: the list of guides is now a responsive grid, and the list is generated from the new cww.json file.
• Links under the .main class are now red by default instead of black - to help distinguish bolded text from links.

[KevinPayravi]

I did consider just adding CWW links to the members.json file, but the guide links and wikis participating each year changes.

[KevinPayravi]

Just remembered that the CWW gudie links should be leveraging the URLs from members.json, I'll update that soon.