The doc url should be case insensitive

let's consider the following senario :

If I've already opened  http://doc.qt.io/qt-5/qsqltablemodel.html in my browser , and then  I want to visit the doc of QStatusBar(I got the class name from code editor ),  the easiest want to do is perhaps  to replace qsqltablemodel in the above url with QStatusBar and then press enter key in browser address bar, however ,   http://doc.qt.io/qt-5/QStatusBar.html just show 404, one could only visit http://doc.qt.io/qt-5/qstatusbar.html, so for convenience , I'd suggest the doc url should be case insensitive