demo: Use properties instead of attributes for <link>
demo: Use properties instead of attributes for <link>

Follows-up 953c46c4.

Change-Id: Ib07ce37f722e8df4774553e90bae650204a2602e

wikimedia/oojs-ui,wikimedia/oojs-ui,wikimedia/oojs-ui,wikimedia/oojs-ui