Fix main nav function syntax issue.

www/guide/interface.md

@@ -14,3 +14,12 @@
  - The turn counter is displayed in the top-right corner.
  - The status of the game may be displayed in the bottom-left corner.
  - If the user hovers over a tile, the position and piece are displayed in the top-left corner.
+
+
+## Practice Mode
+
+### Auto Play
+
+Auto play makes moves for one player using a forward-looking score-based algorithm.
+
+To start auto play, click the Auto button; auto play selects a player based on the rotation of the board.

www/js/ui.js

@@ -103,7 +103,7 @@ const UI = {
             left.appendChild(UI.button("Register", () => { LOAD_STACK(SCENES.Register); }));
             left.appendChild(UI.button("Log In", () => { LOAD_STACK(SCENES.Authenticate); }));
         } else {
-            left.push(UI.button("Start", () => { MESSAGE_SESSION_START(); }));
+            left.appendChild(UI.button("Start", () => { MESSAGE_SESSION_START(); }));
         }
 
         for(child of left_children) { left.appendChild(child); }