Config Transactional Email Template Definition

<config>
    <global>
        <template>
            <email>
                <your_module_email_something_template translate="label" module="namespace_module">
                    <label>Something</label>
                    <file>namespace/module/something.html</file>
                    <type>html</type>
                </your_module_email_something_template>
            </email>
        </template>
    </global>
</config>