Added multiple services to the providers list

Hello Cal!

I Added a bunch of providers to the list. On the other hand, there are a couple of providers that dont follow "strictly" the oembed spec, I put them at the end of the list, so you can choose what to do. The commit message has more information about each provider.

Since the list is rather long, it would be a good idea to consider splitting the provider list into another html file. Show the popular ones on the index.html and from there link to a 'providers.html' with the full list of providers.