Improve map help text

www/pages/help/map.html

@@ -39,6 +39,14 @@
                     and
                     <span class="button button-small display-inline button-fill color-white text-color-black"><i class="fas fa-minus"></i></span>
                     to zoom in and out.
+
+                    <br />
+
+                    Drag on
+                    <span class="button button-small display-inline button-fill color-white text-color-black"><i class="fas fa-sort"></i></span>
+                    to rotate and tilt the map.  Dragging left and right rotates, up and down tilts.
+                    You can also rotate with two fingers by twisting them around each other,
+                    or with a keyboard by holding Ctrl and dragging the mouse.
                 </div>
 
                 <div class="block-title">Follow Location</div>