Minimum requirement is java 8 or above

docs/pages/7_0_0_release_notes.md

@@ -210,6 +210,8 @@ This should help us in future development.
 
 #### Compatibility and migration notes
 
+PMD 7 requires Java 8 or above to execute.
+
 TODO - what to look out for. Hints and known problems.
 
 #### New Rules

docs/pages/pmd/userdocs/installation.md

@@ -11,13 +11,10 @@ sidebar: pmd_sidebar
 
 ### Requirements
 
-*   [Java JRE](http://www.oracle.com/technetwork/java/javase/downloads/index.html),
+*   Java 8 or above: [Java JRE](http://www.oracle.com/technetwork/java/javase/downloads/index.html),
     OpenJDK from [Azul](https://www.azul.com/downloads/zulu-community/)
-    or [AdoptOpenJDK](https://adoptopenjdk.net/) 1.7 or higher.
-    
-    **Note:** For analyzing Apex, HTML, JavaScript, Scala or VisualForce or running the [Designer](pmd_userdocs_extending_designer_reference.html)
-    at least Java 8 is required.
-    
+    or [Adoptium](https://adoptium.net).
+
 *   A zip archiver, e.g.:
     
     * For Windows: [Winzip](http://winzip.com) or the free [7-zip](http://www.7-zip.org/)