How to install ICE for TinyMCE in Plone 5

Plone Support
1

Hi there,
I am trying to install this Plugin for the TinyMCE: https://github.com/NYTimes/ice

I modified registry.xml like this:

<record name="plone.custom_plugins" interface="Products.CMFPlone.interfaces.controlpanel.ITinyMCESchema" field="custom_plugins">
	<field type="plone.registry.field.List">
		<value_type type="plone.registry.field.TextLine" />
	</field>
	<value key="js">
		<element>ice|++resource++ldkiid.base.scripts/ice-master/ice-master.min.js</element>
	</value>
</record>

<record name="plone.custom_buttons" interface="Products.CMFPlone.interfaces.controlpanel.ITinyMCESchema" field="custom_buttons">
	<field type="plone.registry.field.List">
		<value_type type="plone.registry.field.TextLine" />
	</field>
	<value>
		<element>ice_togglechanges</element>
		<element>ice_toggleshowchanges</element>
		<element>iceacceptall</element>
		<element>icerejectall</element>
		<element>iceaccept</element>
		<element>icereject</element>
	</value>
</record>

If I run a quickinstall my registry entries are visible in the TinyMCE configuration but not in the editor itself. I am not sure if it finds the js file or if I have to do something for this. Maybe initializing ICE? But how?