Link to the LTN tool on the web index

Author: dabreegster

web/src/web_root/index.html

@@ -8,6 +8,7 @@ <h1>Apps</h1>
             <li><a href="abstreet.html">A/B Street</a></li>
 	    <!-- Just sticking this in here for convenience, until the tool is split out -->
 	    <li><a href="abstreet.html?--ungap&system/us/seattle/maps/udistrict.bin">Bike network tool</a></li>
+	    <li><a href="abstreet.html?--ltn&system/gb/leeds/maps/north.bin">LTN tool (experimental)</a></li>
             <li><a href="fifteen_min.html">Fifteen Minute Neighborhood Tool</a></li>
             <li><a href="osm_viewer.html">OSM Viewer</a></li>
             <li><a href="widgetry_demo.html">Widgetry Demo</a></li>