11ty: Convert href links to markdown (.md) files to directory path links

.eleventy.js

const markdownEngine = markdownIt({
  html: true,
  linkify: true
});

const defaultRender = markdownEngine.renderer.rules.link_open || function(tokens, idx, options, env, self) {
  return self.renderToken(tokens, idx, options);
};

markdownEngine.renderer.rules.link_open = function (tokens, idx, options, env, self) {
  const isMarkDownLink = tokens[idx].attrGet('href').search('.md') !== -1;

  if (isMarkDownLink) {
    let newLink = tokens[idx].attrGet('href').replace('.md', '');
    tokens[idx].attrSet('href', newLink);
  }

  return defaultRender(tokens, idx, options, env, self);
};