Bibliography styling

[cristian-5]

We should have a selector in the theme.yml that allows us to change the appearance of the bibliography item list, something like this:

bibliography:
  item-spacing: 6
  font-color: #000000
  style: circle
  link-color: #FF0000

Note the style property allowing us to chose from different list styles, with the addition of none to hide the bullet point.
Also note the link-color that only applies to external links in the bibliography.

[cristian-5]

@mojavelinux related to the issue on the other repo