Added bottom margin to dynamic content.

I.e. the credits and search results lists, so that they don't end flush
with the base of the browser window.

credits.html

@@ -5,6 +5,9 @@ permalink: /credits/
 ---
 
 <style>
+#contrib {
+    margin-bottom: 16px;
+}
 #contrib > paper-item {
     display: inline-block;
     margin: 2px;

search.html

@@ -7,6 +7,7 @@ permalink: /search/
 <style>
 #results {
     background: white;
+    margin-bottom: 16px;
 }
 #progress.hidden {
     display: none;