Update changes for 1.3.6

docs/reference/changes.md

 # Change log
 
+## 1.3.6
+
+- Fix a PHP 8.1 warning in certain situations
+- Adds Inlay.get API parameter to get the config array without validating
+  (useful for upgrader scripts).
+
 ## 1.3.5
 
 - Same as 1.3.4 but with minified production build of the .js files. Saves ~3kB.