Consolidate sample data for the Getting Started Tutorial into one location

[debadair]

Currently, the sample data for the tutorial lives in three different places: the elastic docs repo, a GitHub account, and download.elastic.co. We should have a single location for storing download files that are referenced in the docs. Perhaps the elastic/examples repo?

[epixa]

A million times, yes. This is a ticking time bomb.

[debadair]

Determined that the right thing to do is put all of the sample data sets in S3 with the log file dataset. Going forward, any time we need to link to files from the docs, we'll put them in S3.