Adding transalation of git for pt-pt

Replicated the main git file in Portuguese (from Portugal) lang.

pt-pt is the parent language of pt-br, but different in many ways. Being my mother language I translated into pt-pt and created the corresponding folder better indicate what flavor of portuguese users will find. However, this should now be readable by natives from Portugal, Brazil and the rest of portuguese-based countries.

Portuguese (PT, BR or others) speaking colleagues across the internet are more than welcome to provide feedback and improvements to this translation.

PS: I noticed that other lang files didn't seem to mention the contributors of the english tutorial. I followed this apparent rule, but tell me if I didn't understood correctly the policy. Will be more than happy to provide kudos to the original contributors.