Starting Portuguese Translation

Add README.
[pt-BR] Add file novice/git/00-intro.md based on 5c1b655
[pt-BR] Full translation of novice/git/00-intro.md based on 5c1b655
[pt-BR] Add file novice/git/01-backup.md based on eed8217
[pt-BR] Translate part of novice/git/01-backup.md based on eed8217
[pt-BR] Finish translation of novice/git/01-backup.md based on eed8217
[pt-BR] Add file novice/git/02-collab.md based on 742941c
[pt-BR] Finish translation of novice/git/02-collab.md based on 742941c
[pt-BR] Add file novice/git/03-conflict.md based on 9d183c9
[pt-BR] Finish translation of novice/git/03-conflict.md based on 9d183c9
[pt-BR] Add file novice/git/04-open.md based on a6fd62d
[pt-BR] Finish translation of novice/git/04-open.md based on a6fd62d
Update homepage ...

and add links to lessons and translated version of it.