<idea-plugin>
  <id>com.my.plugin</id>
  <extensionPoints>
    <extensionPoint name="intentionAction"
                    beanClass="com.intellij.lang.LanguageExtensionPoint">
      <with tag="className" implements="MyLanguageExtensionPointInterface"/>
    </extensionPoint>
  </extensionPoints>

  <extensions defaultExtensionNs="com.my.plugin">
      <intentionAction language="">
          <className>MyLanguageExtensionPoint</className>
      </intentionAction>
  </extensions>
</idea-plugin>