code: function capSplitAndJoin(joiner, options) {
    const string = options.fn(this);
    const members = string.split(/(?=[A-Z])/);
    return members.join(joiner);
  }
docs: Split a string by capital letters and then re-join by another.
  @param {string}      joiner        - String to join with
  @param {object}      options       - Handlebars options.
  @return {string}                   - Handlebars result