Update to parent 19 and Doxia 2

pom.xml

@@ -4,7 +4,7 @@
   <parent>
     <groupId>org.codehaus.plexus</groupId>
     <artifactId>plexus</artifactId>
-    <version>16</version>
+    <version>19</version>
   </parent>
 
   <artifactId>plexus-site</artifactId>

src/site/site.xml

@@ -1,11 +1,32 @@
-<?xml version="1.0"?>
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+Licensed to the Apache Software Foundation (ASF) under one
+or more contributor license agreements.  See the NOTICE file
+distributed with this work for additional information
+regarding copyright ownership.  The ASF licenses this file
+to you under the Apache License, Version 2.0 (the
+"License"); you may not use this file except in compliance
+with the License.  You may obtain a copy of the License at
 
-<project xmlns="http://maven.apache.org/DECORATION/1.8.0"
-  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-  xsi:schemaLocation="http://maven.apache.org/DECORATION/1.8.0 https://maven.apache.org/xsd/decoration-1.8.0.xsd"
-  name="Plexus">
-  <version position="none" />
+  http://www.apache.org/licenses/LICENSE-2.0
 
+Unless required by applicable law or agreed to in writing,
+software distributed under the License is distributed on an
+"AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+KIND, either express or implied.  See the License for the
+specific language governing permissions and limitations
+under the License.
+-->
+<site xmlns="http://maven.apache.org/SITE/2.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+      xsi:schemaLocation="http://maven.apache.org/SITE/2.0.0 https://maven.apache.org/xsd/site-2.0.0.xsd">
+
+<version position="none" />
+
+  <skin>
+    <groupId>org.apache.maven.skins</groupId>
+    <artifactId>maven-fluido-skin</artifactId>
+    <version>2.0.0-M11</version>
+  </skin>
   <custom>
     <fluidoSkin>
       <sourceLineNumbersEnabled>true</sourceLineNumbersEnabled>
@@ -66,4 +87,4 @@
       <item name="Get Involved" href="/get-involved.html" />
     </menu>
   </body>
-</project>
+</site>