List icon configurable (#152)

List icon made configurable by introducing ul-li-icon CSS variable

exampleSite/layouts/partials/custom_head.html

@@ -14,11 +14,15 @@
     --section-light-bg-color: #ffdb8c!important;
     --section-dark-bg-color: #035e00!important;
     */
+
+     /* define list element for unnumbered lists, leave empty for default list element */
+     /* fa-asterisk is the default icon if this variable definition is missing completely */
+     --ul-li-icon: fa-dashcube;     /* this sets fa-dashcube as list icon */
+     --ul-li-icon: ;                /* this sets the default html list icon */
 }
 </style>
 -->
 
-
 <!-- Custom CSS via "custom.css"-file
      If you would rather place your custom CSS into
      a separate file, create a "custom.css" in your