02-getting-started completado

Último commit traducido:
https://github.com/DiscoverMeteor/DiscoverMeteor_En/commit/58034940b7728
78344ec6b4f6aa82f2fccd4d9d7#diff-b1468c225c3cc69398a3262b4b66cbde
Merge pull request #34 from p4bloch/master

02-getting-started completado