Update pt.json

- Changed indentation according to Node.js Style Guide (as per @psaints suggestion);
- Changed duration unit from "min" to "minutos";
- Changed Portuguese languages names to identify the country in parenthesis, ex: "Português (Brasil)" instead of "Português do Brasil" or "Português Brasileiro";
- Switched words according to the orthographic agreement for their pre-orthographic agreement equivalents;

...to be reviewed...