Small change to Argon template

I added an option to the nice Argon dokuwiki template to get rid of the left sidebar. Here are the changes I made:

1. Changes to main.php (lib/tpl/argon/)
   • Top of the file, below original line 10, add the line:

     $showLeftSidebar = !tpl_getConf('hideLeftSidebar');

   • Below line 133 (original line 132, after the left sidebar comment), add the line:

     <?php if ($showLeftSidebar) { ?>

   • Around line 198, after the code

     <!-- center content -->
     <main class="col-12 col-md-9 col-xl-8 py-md-3 pl-md-5 ct-content dokuwiki" role="main">

     add the following three lines:

     <?php } else { ?>
     <main class="col-12 col-md-115 col-xl-10 py-md-3 pl-md-5 ct-content dokuwiki" role="main">                  
     <?php }?>