CSS

Download and install a Bootstrap theme. Modify the following at

vi bootstrap/templates/menu/system/form-element.func.php

li:before {
  position: absolute;
  top: 0;
  left: 0;
  font-family: 'FontAwesome';  /* Specify FontAwesome   */
  content: '\f07b';            /* This is a folder icon */
  color: #fab100;              /* Yellow                */
}

li  {
  position: relative;    /* Line breaks without this                       */
  padding-left: 20px;    /* Add a padding for the size of Fontawesome icon */
                         /* at the left of the bullet item                 */
  list-style-type: none; /* Display bullet dot（・）without this            */
}