Book translation to pt-BR

[netrik182]

Hi @serhack!

Here's the translation of Mastering Monero (First Edition) as a result of the work I did within my CCS proposal. It's been already reviewed my @nelsonrenan while I was commiting to my own repo and his suggestions were added on commits 98d7c6f 30e049f 5f8ef60.

Pinging @botoserelepe as well

P.S.: I cleanly don't want to merge into master, maybe we could have a separate branch for it?