Hosting on github pages

[ericwooley]

Wemips is now hosted on github pages, at wemips.dev.plumbing, which should always stay up to date with the latest changes.

@ralfgerlich Up to you if you want to keep hosting yours or not 🤷

The github pages version should have the advantage of always staying up to date. In any case, I just added a not to the section on the readme about the hosted versions, which links to both.