chapter 5 translation, few other translation examples added to translation-guidelines.txt
Merge pull request #444 from gibas/05-distributed-git

[pl] chapter 5 translation, few other translation examples added to translati...
speling fixes, added blank line between polish and oryginal text
small fix in section name
Merge pull request #447 from gibas/spelling-fixes

[pl] small fix in section name in chapter 3
Merge pull request #446 from gibas/05-distributed-git

[pl] spelling fixes, add blank line between polish and original text