Update changelog

docs/pages/release_notes.md

@@ -13,12 +13,25 @@ This is a bug fixing release.
 ### Table Of Contents
 
 * [New and noteworthy](#new-and-noteworthy)
+  * [Disable Incremental Analysis](#disable-incremental-analysis)
 * [Fixed Issues](#fixed-issues)
 * [API Changes](#api-changes)
 * [External Contributions](#external-contributions)
 
 ### New and noteworthy
 
+### Disable Incremental Analysis
+
+Some time ago, we added support for [Incremental Analhysis](pmd_userdocs_getting_started.html). On PMD 6.0.0, we
+started to add warns when not using it, as we strongly believe it's a great improvement to our user's experience as
+analysis time is greatly reduced; and in the future we plan to have it enabled by default. However, we realize some
+scenarios don't benefit from it (ie: CI jobs), and having the warning logged can be noisy and cause confusion.
+
+To this end, we have added a new flag to allow you to explicitly disable incremental analysis. On CLI, this is
+the new `-no-cache` flag. On Ant, there is a `noCache` attribute for the `<pmd>` task.
+
+On both scenarios, disabling the cache takes precedence over setting a cache location.
+
 #### Ecmascript (JavaScript)
 
 The [Rhino Library](https://github.com/mozilla/rhino) has been upgraded from version 1.7.7 to version 1.7.7.2.
@@ -48,4 +61,4 @@ Both are bugfixing releases.
 ### External Contributions
 
 * [#941](https://github.com/pmd/pmd/pull/941): \[java] Use char notation to represent a character to improve performance - [reudismam](https://github.com/reudismam)
-* [#943](https://github.com/pmd/pmd/pull/943): \[java] UnusedPrivateField false-positive with @FXML - [BBG](https://github.com/djydewang)
+* [#943](https://github.com/pmd/pmd/pull/943): \[java] UnusedPrivateField false-positive with @FXML - [BBG](https://github.com/djydewang)