fix calculation

Author: UziTech

lib/marked.js

@@ -728,7 +728,7 @@ InlineLexer.prototype.output = function(src) {
     if (cap = this.rules.link.exec(src)) {
       var lastParenIndex = findClosingBracket(cap[2], '()');
       if (lastParenIndex > -1) {
-        var linkLen = cap[0].length - (cap[2].length - lastParenIndex) - (cap[3] || '').length;
+        var linkLen = 4 + cap[1].length + lastParenIndex;
         cap[2] = cap[2].substring(0, lastParenIndex);
         cap[0] = cap[0].substring(0, linkLen).trim();
         cap[3] = '';