Add support for Portuguese verbs

The translations were provided by [[User:Ederporto]] [1] (slightly edited by
me) and the templates by [[User:Carybe]] [2] and [[User:Joalpe]] [3] at
[[User:Lucas Werkmeister/Wikidata Lexeme Forms/Portuguese]] [4] – thank you!

[1]: https://www.wikidata.org/wiki/User:Ederporto
[2]: https://www.wikidata.org/wiki/User:Carybe
[3]: https://www.wikidata.org/wiki/User:Joalpe
[4]: https://www.wikidata.org/wiki/User:Lucas_Werkmeister/Wikidata_Lexeme_Forms/Portuguese