Add PT-BR Translation: Readme, Quizzes and Introduction (#377)

* Create translation for pt-br

* fix: fix typo error

* fix: fix typo error

* feat: translate quiz

* feat: add translation for pt-br for introduction

* feat: add intro to ml pt-br translate

* feat: add pt-br translation for history of ml

* fix paths

* fix paths

* fix paths

* fix paths and add fairness pt-br translation

* feat: add techniques of ml pt-br translation

* fix quizzes path