code: function createIndex(addFn) {
    return lunr(/** @this */function() {
      this.pipeline.remove(lunr.stopWordFilter);
      this.ref('path');
      this.field('titleWords', {boost: 100});
      this.field('headingWords', {boost: 50});
      this.field('members', {boost: 40});
      this.field('keywords', {boost: 20});
      addFn(this);
    });
  }
docs: Create the lunr index - the docs should be an array of objects, each object containing the path and search terms for a page