Add a prototype railroad track tool

index.html

@@ -202,7 +202,9 @@
             </div>
             <div class="-buttons">
                 <button id="editor-share-url" type="button">Share?</button>
+                <!--
                 <button id="editor-toggle-green" type="button">Toggle green objects</button>
+                -->
             </div>
             <!--
             <p style>