Update the README for the 0.19.0 release (#1724)

Author: gpetiot

CHANGES.md

@@ -1,8 +1,4 @@
-### unreleased
-
-#### Removed
-
-#### Deprecated
+### 0.19.0 (2021-07-16)
 
 #### Bug fixes
 

README.md

@@ -54,7 +54,7 @@ Moreover if you adopt OCamlFormat in one project it will not break your workflow
 The recommended way is to use a versioned default profile, such as:
 
 ```
-version=0.18.0
+version=0.19.0
 ```
 
 (or replace with the output of `ocamlformat --version`)