implement macros

dist/hopdown.js

@@ -39,10 +39,15 @@ function escapeHtml(source) {
  */
 class HopDown {
     tags;
+    macros = null;
     tokenizer;
     constructor(tags) {
         this.tags = tags || defaults_1.defaultTags;
         this.tokenizer = new tokenizer_1.Tokenizer(this.tags);
+        var macroTags = this.tags.map.get(':::');
+        if (macroTags) {
+            this.macros = macroTags[0];
+        }
     }
     /**
      * Convert a markdown string to tokens.