readme: Use <br/> instead of <br> to satisfy gitblit's Markdown parser
readme: Use <br/> instead of <br> to satisfy gitblit's Markdown parser

Change-Id: I0b7f5ff6089d391cf808cf8cbb9c36243b59d755

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