Translates developer docs to brazilian portuguese

[Phe0]

I have verified that this pull request:

• has no linting errors (npm run lint)
• is from a uniquely-named feature branch and has been rebased on top of the latest master. (If I was asked to make more changes, I have made sure to rebase onto master then too)
• is descriptively named and links to an issue number, i.e. Fixes #123

Fixes #1320

[welcome]

🎉 Thanks for opening this pull request! Please check out our contributing guidelines if you haven't already.

[catarak]

I made a large feature merge ~1 wk ago and some of the docs have been updated. Would it be possible to get this in sync with master? Thank you!

[Phe0]

sure @catarak , I'll work on it

[Phe0]

@catarak I've updated the README translation and added translations for public_api_proposed.md and public_api.md

[catarak]

Amazing! So cool. Thank you!

There's something funky happening with your git history here. It says you're trying to merge in 250+ commits? Did you rebase to get to up to date with the tip of master?

[Phe0]

Amazing! So cool. Thank you!

There's something funky happening with your git history here. It says you're trying to merge in 250+ commits? Did you rebase to get to up to date with the tip of master?

Yes @catarak, I've rebased from the upstream master to get it up to date.

[raclim]

Merging this in :)