Update CHANGELOG.md

Author: freekmurze

CHANGELOG.md

@@ -1,24 +1,27 @@
-#Changelog
+# Changelog
 
 All notable changes to `url-signer` will be documented in this file
 
-# 1.2.1 - 2021-02-05
+## 1.2.1 - 2021-02-05
 
 - improve depdendencies
 
-# 1.2.0 - 2020-12-02
+## 1.2.0 - 2020-12-02
 
 - support PHP 8.0
 
-# 1.1.0 - 2020-07-20
+## 1.1.0 - 2020-07-20
 
 - replace league/url with league/uri & league/uri-components (#25)
 
-# 1.0.2 - 2017-04-09
+## 1.0.2 - 2017-04-09
+
 - use `hash_equals` to avoid timing attacks
 
-# 1.0.1
+## 1.0.1
+
 - Fixed: using empty signature keys is not allowed
 
-# 1.0.0
+## 1.0.0
+
 - First release