[-Leocat]

Hello! I have wanted to make an Add-On for KODI. So I started out with an example. After I have got an Idea about what I'm going to make I started to add some menus. Without success. Well this is my addon.xml:
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<addon id="script.hello.world" name="Hello World" version="1.0.2" provider-name="zag">
    <requires>
        <import addon="xbmc.python" version="2.23.0"/>
    </requires>
    <extension point="xbmc.python.script" library="addon.py">
        <provides>executable</provides>
    </extension>
    <extension point="xbmc.addon.metadata">
        <platform>all</platform>
        <summary lang="en">Popup Hello World</summary>
        <description lang="en">Example Script to show Hello World</description>
        <license>GNU General Public License, v2</license>
        <language></language>
        <forum>http://forum.kodi.tv/showthread.php?tid=209948</forum>
        <source>https://github.com/zag2me/script.hello.world</source>
        <website>Kodi.tv</website>
        <email>zag@kodi.org</email>
        <assets>
            <icon>icon.png</icon>
            <fanart>fanart.jpg</fanart>
            <screenshot>resources/screenshot-01.jpg</screenshot>
            <screenshot>resources/screenshot-02.jpg</screenshot>
            <screenshot>resources/screenshot-03.jpg</screenshot>
        </assets>
        <news>Updated the addon to use new addon.xml metadata</news>
    </extension>
<extension point="kodi.context.item">
<menu id="kodi.core.main">
  <menu>
    <label>My submenu</label>
    <item library="contextitem1.py">
      <label>30001</label>
      <visible>true</visible>
    </item>
    <item library="contextitem2.py">
      <label>30002</label>
      <visible>true</visible>
    </item>
    <menu>
      <label>Subsubmenu</label>
      <item library="contextitem3.py">
        <label>30003</label>
        <visible>true</visible>
      </item>
    </menu>
</menu>
</extension>
</addon>