l10n: Full PT-BR translation (#4882)

* devise.pt-BR.yml now fully translated

* pt-BR.json now fully translated

* pt-BR.yml partially translated; 46 lines left

* pt-BR.yml now fully translated

* simple_form.pt-BR.yml fully translated

* doorkeeper.pt-BR.yml now fully translated

* E-mail instructions on app/views/user_mailer added and fully translated

* PT-BR translation for #4871

* Deleted an unwanted caracter on pt-BR.yml

* Fixing typos on pt-BR.yml

* Added translation for Pinned toots tab on pt-BR.json

* Added missing translation for navigation_bar.pins