Updates README.md to use ruby syntax highlight
Adds missing codes	

* New carriers Nextel (non-Radio), Datora and
Porto;
* New error codes
Returns server error if carrier code is not present
Fixes Brazilian phone format

This fix accounts for the relatively stable format
of area codes in Brazil since number of grantable
cellphones are usually increased by adding another
digit in the number format. The format is
described in Resolution 263 from Anatel. 

Also, fixes the extra digit rule, in which it's
possible to have any digit after the extra 9.
Bumps version