Fix shortcode name on readme example

[leonardoalifraco]

There was a mistake on the shortcode name on the documentation.

[thunderer]

Hi @leonardoalifraco, thanks for the fix! Seems that I didn't run this example in the interpreter to check. Is there anything else I can do for you with regards to this library? I'm always looking for fresh ideas from people that use my code. :)

[leonardoalifraco]

Hi @thunderer

The library works great! I've just started using it today for a job related project.
If I come with something to change or improve I'll let you know.

Thanks a lot!