updated readme.md

Tsung-Wei Huang · Tsung-Wei Huang · commit 72c30cf40938 · 2018-06-12T21:50:01.000-04:00
diff --git a/README.md b/README.md
@@ -107,6 +107,7 @@ tf.linearize(A, B, C, D);  // A runs before A, B runs before C, and C runs befor
 
 ## Step 3: Execute the Tasks
 There are three methods to carry out a task dependency graph, `dispatch`, `silent_dispatch`, and `wait_for_all`.
+
 ```cpp
 auto future = tf.dispatch();  // non-blocking, returns with a future immediately.
 tf.silent_dispatch();                // non-blocking, no return
@@ -150,7 +151,6 @@ digraph Taskflow {
 ```
 There are a number of free [GraphViz tools][AwesomeGraphViz] you could find online
 to visualize your Taskflow graph.
-
 <img src="image/graphviz.png" width="25%"> Taskflow with five tasks and six dependencies, generated by [Viz.js](http://viz-js.com/).
 
 # API Reference
