revert blog index and delete ds_store

.gitignore

@@ -1,3 +1,4 @@
 *~
 .sass-cache/
 _site/
+.DS_Store

blog/index.md

@@ -0,0 +1,12 @@
+----
+layout: page
+title: Blog
+excerpt: "An archive of blog posts sorted by date."
+search_omit: true
+----
+
+<ul class="post-list">
+{% for post in site.categories.blog %} 
+  <li><article><a href="{{ site.url }}{{ post.url }}">{{ post.title }} <span class="entry-date"><time datetime="{{ post.date | date_to_xmlschema }}">{{ post.date | date: "%B %d, %Y" }}</time></span>{% if post.excerpt %} <span class="excerpt">{{ post.excerpt | remove: '\[ ... \]' | remove: '\( ... \)' | markdownify | strip_html | strip_newlines | escape_once }}</span>{% endif %}</a></article></li>
+{% endfor %}
+</ul>