Update README.md

Author: Cheng-Lin-Li

A-Priori_SON/README.md

@@ -35,16 +35,16 @@ next, it makes second pass through data to determine which candidates are global
 Each line of the file contains one itemset (a list of comma-separated item numbers). The order doesn’t matter. 
 
     For example
-      4
-      1,3,4 
+      4
+      1,3,4 
       1,2,3 2
-      1,3 2,4 
+      1,3 2,4 
       2,3 1
-      2,3,4 
+      2,3,4 
       1,4 
       3
-      3,4
-      1,2,4 
+      3,4
+      1,2,4 
       2,5 
       1,2 
       5