Set up a demo

First off, thanks for open sourcing this application! This is a suggestion to increase the amount of people that would make use of it: an example in the readme file would help.

Currently, users have to clone the app, install it, authorize through pocket, run a command, an then find out if this application does what they hope it does.

Another possibility is to add a file `example-output.db`, containing one (mock) Pocket article.

Keep up the good work!