Update changelog for 2.0.0

CHANGES.md

@@ -1,15 +1,11 @@
-### unreleased
+### 2.0.0
 
 #### Added
 
 - Add trailing `;;` to the output of toplevel phrases that were missing it.
   (#346, @Leonidas-from-XIV)
 - Make MDX compatible with OCaml 4.14 (#356, @NathanReb)
 
-#### Changed
-
-#### Deprecated
-
 #### Fixed
 
 - Use the same output as the normal toplevel. Mdx used to carry an unsafe patch
@@ -26,8 +22,6 @@
   instead. This label was only used for the `rule` command and can now be
   safely removed. (#363, @Leonidas-from-XIV)
 
-#### Security
-
 ### 1.11.0
 
 #### Added