* Add translation to Portuguese for [History, Design and Future - História, Design e Futuro](https://fastapi.tiangolo.com/pt/history-design-future/). PR [#1249](https://github.com/tiangolo/fastapi/pull/1249) by [@marcosmmb](https://github.com/marcosmmb).

	At most one of the type parameters has a known type argument.
	In this case, the type parameters are <i>joined</i>:
	they both stand for the same type argument.
	If neither type parameter has a known type argument yet,
	a future type argument inferred for one the type parameters
	is simultaneously inferred for both of them.
</li>
<li>
	Both type parameters have a known type argument