update docs

website/docs/configuration.md

@@ -32,6 +32,7 @@ body = """
 """
 trim = true
 footer = "<!-- generated by git-cliff -->"
+postprocessors = [{ pattern = "foo", replace = "bar"}]
 ```
 
 <!-- {% endraw %} -->
@@ -56,6 +57,12 @@ It is useful for adding indentation to the template for readability, as shown [i
 
 Footer text that will be added to the end of the changelog.
 
+### postprocessors
+
+An array of commit preprocessors for manipulating the changelog before outputting.
+Can e.g. be used for replacing commit author with github user names.
+See [commit_preprocessors](#commit_preprocessors) for more detail and examples, it uses the same syntax.
+
 ## `git`
 
 This section contains the parsing and git related configuration options.