portuguese corrections for _config.yml
Update _posts/pt/0100-01-01-404.md

Proof reading for pt
Update _posts/pt/0100-01-01-contribute.md

Portuguese proof reading
Update _posts/pt/0100-01-01-index.md

Portuguese proof reading
Update _posts/pt/0100-03-01-beginner.md

Portuguese proof reading
files renamed and some corrected errors
Some corrections
Links corrected, proof reading of introduction
Merge changes from https://github.com/hotosm/learnosm/pull/37.
Take over @vgeorge's naming scheme.
Small touches to adjust to newer English version.
Merge pull request #43 from hotosm/vgeorge

Corrections to Portuguese - thanks @vgeorge