Demos: Pre-render collapsibles in demos left-side menu
Demos: Pre-render collapsibles in demos left-side menu

Fixes gh-7225

hinaloe/jqm-demo-ja,hinaloe/jqm-demo-ja,hinaloe/jqm-demo-ja,arschmitz/uglymongrel-jquery-mobile,arschmitz/uglymongrel-jquery-mobile,arschmitz/uglymongrel-jquery-mobile