Use file extensions, at least for non-HTML files about whatwg.org

[annevk]

We could add extensions elsewhere too to make local viewing less cumbersome and use .htaccess to rewrite the URLs.

[foolip]

I guess we could also trim some htaccess files this way.

[domenic]

Part of the solution here might be Alias directives in .htaccess, which map URLs to filesystem files. So we could alias the extension-less URLs to the extension-ful files. That seems a bit strange though if we want to have a single canonical URL though, as then you could still access both the extension-less URL and the extension-ful one, I think.

[annevk]

Note that we need to preserve the URLs even of the stylesheets and images, as they are linked from legacy documents. So overall we could maybe do this for new resources, but it's not something I'm super interested in taking on for all the existing resources.

[annevk]

I think the consensus here is that we do this for new things, but refactoring old stuff is too involved.