feat: make oembed requests default to json type

[MichaelDeBoey]

No need to pass format if their's only one.

We can make it default to json whenever we would want to support xml format too

[smeijer]

Don't we need to throw a 501 NOT IMPLEMENTED if the consumer asks for format=xml?

That would mean we can just change the condition:

- params.format !== 'json'
+ params.format === 'xml'

[MichaelDeBoey]

@smeijer Fixed 🙂

[smeijer]

Thanks 😎

@all-contributors please add @MichaelDeBoey for code

[allcontributors]

@smeijer

I've put up a pull request to add @MichaelDeBoey! 🎉

[MichaelDeBoey]

It's a pleasure to help out! 🙂