chore(changelog): add audit --level flag

CHANGELOG.md

@@ -6,6 +6,10 @@ Please add one entry in this file for each change in Yarn's behavior. Use the sa
 
 ## 1.15.0
 
+- Implements `yarn audit --level [severity]` flag to filter the audit command's output.
+
+[#6716](https://github.com/yarnpkg/yarn/pull/6716) - [**Rogério Vicente**](https://twitter.com/rogeriopvl)
+
 - Removes `--scripts-prepend-node-path` as Yarn's default behavior makes this obsolete
 
   [#7057](https://github.com/yarnpkg/yarn/pull/7057/files) - [**Jason Grout**](https://github.com/jasongrout)