Fixes bullet list of Zipkin components (#54)

As it isn't rendered correctly on the website.
diff --git a/pages/architecture.md b/pages/architecture.md
index 6c7d42a..ce24c9f 100644
--- a/pages/architecture.md
+++ b/pages/architecture.md
@@ -27,6 +27,7 @@
 There are two primary transports: Scribe and Kafka. Scribe is shown in the figure. See [Span Receivers]({{ site.github.url }}/pages/span_receivers) for more information.
 
 There are 4 components that make up Zipkin:
+
 * collector
 * storage
 * search