Adds images; explains output files. Resolves #103.

[ianmilligan1]

This mostly resolves #103. It does the following:

• adds two images, showing successful output and example files;
• shows a file being opened in TextEdit.

I elected not to add info about cating the files together. We don't have any command line instructions in the tutorial, so this keeps it pretty simple. If we have folks going into the command line to run commands, we'd need a lot more scaffolding.

I think we should merge this ASAP given the datathon, so I'll just look for a quick set of eyes on and a thumbs up.

[ianmilligan1]

Here's what it looks like:

[ruebot]

Should we add a bit about cating the files together?

[ianmilligan1]

I noted above:

I elected not to add info about cating the files together. We don't have any command line instructions in the tutorial, so this keeps it pretty simple. If we have folks going into the command line to run commands, we'd need a lot more scaffolding.

We can put a little note about 'if you know your way around the command line, you can do this..' but I think given it's a little circumscribed run one docker command and cut/paste + use GUI, I don't think we want to worry people too much about cat.

[ruebot]

Heh. Somebody didn't read everything, and looks like a fool.

[ianmilligan1]

Heh, I think our positions have been reversed more often than I'm prepared to admit. 😄

@SamFritz just gave me her thumbs-up in Slack so I'm gonna merge + publish.