intro-to-pd.md

@@ -132,12 +132,25 @@ Press the buttons that correspond to the following numbers to play:
 
 Hot Crossed Buns
 ======
-3  2  1        3   2   1        1  1  1  1  2   2  2  2  3   2    1
+   3  2  1      
+   3   2   1       
+   1  1  1  1  2   2  2  2  
+   3   2    1
 
-Mary had a little lamb
+Mary Had a Little Lamb
 ======
-3  2  1  2  3  3  3       2  2  2      3   3   3       3  2  1  2   3  3  3   3  2   2  3  2  1 
+3  2  1  2  3  3  3       
+2  2  2      3   3   3      
+3  2  1  2   3  3  3   
+3  2   2  3  2  1 
 
+Row Row Row Your Boat
+======
+1  1  1 2 3 
+3  2 3  4 5   
+6 6 6 5 5 5 
+3 3 3 1 1 1
+5 4 3 2 1