Add target='_blank' to promo link

Author: ckenst

_includes/banner.html

@@ -1,5 +1,5 @@
 <script src="//ajax.googleapis.com/ajax/libs/jquery/1.9.1/jquery.min.js"></script>
 <script src="/assets/promo.js" type="text/javascript"></script>
 <div id="promo">
-  Come Jam with PNSQC! <a href="https://mms.pnsqc.org/Calendar/moreinfo.php?org_id=PNSQ&amp;eventid=190750&amp;utm_source=testingconferences" rel="noopener" aria-label="Learn more about the PNSQC Jam event">Learn more</a>.
-</div>
+  Come Jam with PNSQC! <a href="https://mms.pnsqc.org/Calendar/moreinfo.php?org_id=PNSQ&amp;eventid=190750&amp;utm_source=testingconferences" rel="noopener" aria-label="Learn more about the PNSQC Jam event" target="_blank">Learn more</a>.
+</div>