Readme: link to API docs at Cloudflare

[olleolleolle]

In order to be able to explore the possibilities of the library, finding out what the API it wraps can do would help a first-time reader getting familiar with the library.

[nuclearspike]

Nice, I'd add that having more examples of typical things people would be doing would be helpful. Clearing the cache by url, for example is a much more common example than changing DNS entries via API.

[ioquatix]

Feel free to add examples.