It would probably be a good idea to add at least a very basic file template for
new file types, e.g.

    <folder name="Templates">
        <folder name="Other">
            <file name="typenamehere.xml">
                <attr boolvalue="true" name="template"/>
                <![CDATA[<root xmlns="http://the.uri/"/>]]>
            </file>
        </folder>
    </folder>

or

    <folder name="Templates">
        <folder name="Other">
            <file name="typenamehere.extension">
                <attr boolvalue="true" name="template"/>
                <![CDATA[sample contents]]>
            </file>
        </folder>
    </folder>

Enough to get people started, anyway.