Add a JSON file representing videos from 2014.

This PR introduces a `videos.json` file.

As discussed in #6 storing video parameters in a more structured manner will mean they may be accessed programatically. This will in turn allow them to be presented and used in a variety of ways, e.g.:

* Compiled into various document formats, (md, rst etc).
* Compiled into a simple static site, (which might be hosted on github pages).
* As the backend of a simple applciation which downloads the videos using `youtube-dl`.

At present the file includes only videos from 2014. I expect this PR to generate some discussion as to the JSON formatting. Once the format is confirmed and this PR merged, I will go on to create a new PR which adds the videos from previous years,