Update changelog

Author: ehmicky

CHANGELOG.md

@@ -1,3 +1,17 @@
+# 6.0.0
+
+## Breaking changes
+
+- Previously, if the [`props`](README.md#-props) option was `false`,
+  [aggregate errors](https://github.com/ehmicky/modern-errors#aggregate-errors)
+  were not printed. To achieve the same behavior, the
+  [`cause`](README.md#-cause) option must now be set to `false`.
+
+## Features
+
+- Aggregate errors are now printed on their own, which result in a prettier
+  output.
+
 # 5.2.0
 
 ## Features