Standardize dataset description parameters with YAML header

[angela-li]

Currently, there is no standard structure to our data descriptions, which makes it very difficult to use a machine to read the page. I'd like to develop an HTML/CSS template with a YAML header for our data descriptions in posts to standardize our data descriptions. (I can do this by editing the template in initpost.sh I believe - @lixun910 correct me if I'm wrong.)

The idea is to have a YAML header in each post that we fill out, which Jekyll then plugs into a HTML/CSS template with custom tags, that is set up to be easily webscraped and analyzed. This will also make it easier to add and document datasets in the future, without having to worry about formatting/layout.

Here's an example of what I think this would look like:

---
source: Chicago Open Data Portal
author: Luc Anselin
variables: 77 
observations: X
(more YAML parameters...)
---

<h3>Source: </h3>
<p class="source"> {{page.source}}</p>
<h3> Author: </h3>
<p class="author"> {{page.author}} </p>
(more HTML/CSS...)

Note: This idea was inspired by Software Carpentry's workshop website template - see an example here of how this works, and the produced page.

[angela-li]

Set this infrastructure up in 65438b8, still need to fix formatting of the webpage, and move all datasets over to this format.

This will setup will make it possible to tackle #26 relatively easily.