Prepare pmd release 6.20.0

docs/_config.yml

@@ -3,7 +3,7 @@ repository: pmd/pmd
 pmd:
     version: 6.20.0
     previous_version: 6.19.0
-    date: ??-November-2019
+    date: 29-November-2019
     release_type: minor
 
 # release types: major, minor, bugfix

docs/pages/next_major_development.md

@@ -73,6 +73,10 @@ the breaking API changes will be performed in 7.0.0.
 an API is tagged as `@Deprecated` or not in the latest minor release. During the development of 7.0.0,
 we may decide to remove some APIs that were not tagged as deprecated, though we'll try to avoid it." %}
 
+#### 6.20.0
+
+No changes.
+
 #### 6.19.0
 
 ##### Deprecated APIs

docs/pages/release_notes.md

@@ -12,8 +12,6 @@ This is a {{ site.pmd.release_type }} release.
 
 {% tocmaker is_release_notes_processor %}
 
-### New and noteworthy
-
 ### Fixed Issues
 
 *   apex
@@ -39,8 +37,6 @@ This is a {{ site.pmd.release_type }} release.
 *   java-errorprone
     *   [#2102](https://github.com/pmd/pmd/issues/2102): \[java] False positive MissingStaticMethodInNonInstantiatableClass when inheritors are instantiable
 
-### API Changes
-
 ### External Contributions
 
 *   [#2088](https://github.com/pmd/pmd/pull/2088): \[java] Add more version shortcuts for older java - [Henning Schmiedehausen](https://github.com/hgschmie)