code: function Rules (options) {
    this.options = options;
    this._keep = [];
    this._remove = [];
  
    this.blankRule = {
      replacement: options.blankReplacement
    };
  
    this.keepReplacement = options.keepReplacement;
  
    this.defaultRule = {
      replacement: options.defaultReplacement
    };
  
    this.array = [];
    for (var key in options.rules) this.array.push(options.rules[key]);
  }
docs: Manages a collection of rules used to convert HTML to Markdown