addon.xml

<?xml version="1.0"?>
<addon scheme="3.0">
   <id>hello_world</id>
   <version>1.0</version>
   <priority>100500</priority>
   <position>0</position>
   <status>active</status>
   <default_language>en</default_language>
   <auto_install>MULTIVENDOR,ULTIMATE</auto_install>
   <settings edition_type="ROOT,ULT:VENDOR">
        <sections>
            <section id="general">
                <items>
                    <item id="some_prop">
                        <type>input</type>
                        <default_value>Hello World!</default_value>
                    </item>
                    <item id="some_dropdown">
                        <type>selectbox</type>
                        <default_value>blue</default_value>
                        <variants>
                            <item id="red"></item>
                            <item id="green"></item>
                            <item id="blue"></item>
                        </variants>
                    </item>
                </items>
            </section>
        </sections>
    </settings>
</addon>