Implement Journals

Jekyll will follow directory structures, using it as the URL path when
building a site. This significant change adds configuration, styles, and
layouts for journals. Journals will be stored in the `/journals`
directory, and then within a directory for the character.

For each character's journals, configuration must be established in the
`_config.yml` file. Each character journal directory then can be treated
similar to a Jekyll project: the `_posts` directory can be leveraged for
posts. The base character journal directory has an index page, which by
default shows a small top section, then the most recent post. Since
these character journals don't adhere to the actual calendar, permalinks
have been reduced to the post title alone. Note: this means every post
in the character journal must be named different. Not certain if every
post on the site must be named different.

There are a number of steps still left:
- Build site index page. Include cards for each character that has a
  journal, for each adventure, and for any additional miscellaneous
  things captured on the site.
- Implement the adventure section, similar to journals. Any configured
  adventures will exist in the `/adventures` directory, and then within
  a specific directory.
- Actually write stuff.

_includes/journal_footer.html

@@ -0,0 +1,23 @@
+<footer>
+{% assign entries = site.posts | where: "aut", page.aut %}
+
+{% for entry in entries %}
+    {% if entry.id == page.id %}
+        {% assign this_index = forloop.index0 | to_integer %}
+        {% break %}
+    {% endif %} 
+{% endfor %}
+{% assign next_index = this_index | minus: 1 %}
+{% assign prev_index = this_index | plus: 1 %}
+
+{% if prev_index < entries.size %}
+	<span class="previous">
+		<a href="{{ entries[prev_index].url }}">Previous</a>
+	</span>
+{% endif %}
+{% if next_index >= 0 %}
+	<span class="next">
+		<a href="{{ entries[next_index].url }}">Next</a>
+	</span>
+{% endif %}
+</footer>