disable navigation until css is fixed

dev/book/theme/index.hbs

···
                         {{{ content }}}
                     </main>
 
+                    {{#if false}}
                     <nav class="nav-wrapper" aria-label="Page navigation">
                         <!-- Mobile navigation buttons -->
                         {{#if previous}}
···
 
                         <div style="clear: both"></div>
                     </nav>
+		    {{/if}}
                 </div>
             </div>