more markdown compatibility

diff --git a/README b/README
index 8c38760..004e8c2 100644
--- a/README
+++ b/README
@@ -488,7 +488,7 @@ Ie. a value of 8, means 8 times the original size of the initial data.
 The horizontal axis is runtime in seconds, and the '*' represents data points
 showing the trend in use of working space.

-
+```
   9 +-+---------+-----------+-----------+----------+-----------+---------+-+
     +           +           +           +          +           +           +
   8 +-+                                            ****                  +-+
@@ -510,7 +510,7 @@ showing the trend in use of working space.
     *           +           +           +          +           + *         +
   0 *-+---------+-----------+-----------+----------+-----------+-**------+-+
     0          500         1000        1500       2000        2500        3000
-
+```

 -------------------------------------------------------------------------------