Add possibility to skip some HTML tags in processing

[igormironchik]

I'd like to have a possibility to disable emoji conversion in <code> blocks.

[igormironchik]

I solved this issue in my own code with:

function replace_emoji() {
  let elementsToReplace = document.querySelectorAll('p, h1, h2, h3, h4, h5, h6, li, table');
  let elementsToIgnore = document.querySelectorAll('code');
  for (let i = 0; i < elementsToReplace.length; i++) {
    replace_emoji_in_node(elementsToReplace[i]);
  }

  function replace_emoji_in_node(node) {
    if (node.constructor === Text) {
      node.data = emoji.replace_colons(node.data);
    } else if (node.constructor === HTMLScriptElement || [].indexOf.call(elementsToIgnore, node) >= 0) {
      return;
    } else {
      let childNodes = node.childNodes;
      for (let i = 0; i < childNodes.length; i++) {
        replace_emoji_in_node(childNodes[i]);
      }
    }
  }
}