.container .content CSS and .post-item HTML fixes

* .container .content for icons should not be 100%
  to help with centering.
* Use span for .post-item internals, otherwise Firefox
  messes up at smaller screen width with the list bullet
  and title on separate lines.
* README wording

Fix #17

layouts/partials/li.html

@@ -1,4 +1,4 @@
 <li class="post-item">
-    <div class="meta">{{ .Date.Format .Site.Params.DateForm }}</div>
-    <a href="{{ .Permalink }}"><div>{{ .Title }}</div></a>
+    <span class="meta">{{ .Date.Format .Site.Params.DateForm }}</span>
+    <a href="{{ .Permalink }}"><span>{{ .Title }}</span></a>
 </li>