adds the translation file for brazilian portuguese

Hello there! This is funny, because I was looking for a Python module that does precisely the reverse operation that your code does, which means I'm still looking for a solution to "dehumanize" numbers, but then I saw the missing pt_BR translation message in your README and thought that I should fix that :-)

Slightly offtopic but still linguistics-wise: the translation is not 100% accurate as we have different genders for ordinal numbers in portuguese (not particular to the brazilian dialect, it's part of the language itself) but often we just consider them as masculine nouns, hence the ".º" around. Also, besides the 1st, 2nd and 3rd equivalents we have different names for all the other numbers up to 9th, and yet another suffix "-ésimo" for ordinals ending with zero such as 20th, 30th, 40th etc as we don't have anything like "th" in the written form.