Only force URLs from know domains from http:// to https://

[peterbe]

Today, we're turn all external http:// URLs to https:// URLs. That doesn't make sense because some http:// URLs stop working if you do that. (See examples mentioned in the discussion referenced).
But there's still a LOT of http:// URLs that we know with certainty can be automatically converted to https:// for example http://codepen.io/xxx.

Let's only touch those that are safe. We'll do this by checking in a .json file which we maintain offline/manually.

Originally posted by @peterbe in https://github.com/mdn/yari/discussions/3651