Update CHANGELOG to be easier to read

Can't read well currently (unless in raw data form)

Author: PikachuEXE

CHANGELOG.markdown

@@ -2,14 +2,17 @@
 - MAJOR fix in pattern-matching: If the return contract for a pattern-matched function fails, it should NOT try the next pattern-match function. Pattern-matching is only for params, not return values.
 - raise an error if multiple defns have the same contract for pattern matching.
 
-- New syntax for functions with no input params (the old style still works)
+- New syntax for functions with no input params (the old style still works)  
   Old way:
+  ```ruby
   Contract nil => 1
   def one
-
+  ```
   New way:
+  ```
   Contract 1
   def one
+  ```
 
 - Prettier HashOf contract can now be written like this: `HashOf[Num => String]`
 - Add `SetOf` contract