Change DogeAPI to Block.io

I added Block.io instead of DogeAPI in Getting Started (images, description + french description).
I'm not a web developper but i think it's ok....
Maybe you can correct few things and correct my english translations, since I'm french...

I fixed the problem https://github.com/dogecoin/dogecoin.com/pull/52#issuecomment-58221235


"Set your secret PIN with 8 characters at least, it must contain only numbers and letters."
Create a Secret PIN of at least 8 characters (only numbers and letters are allowed).

"Then, click on Set Secret PIN."
Then click Set Secret PIN