Add support of embed pdf

public/js/index.js

@@ -152,6 +152,10 @@ var supportExternals = [
     {
         text: '{%speakerdeck speakerdeckid %}',
         search: 'speakerdeck'
+    },
+    {
+        text: '{%pdf pdfurl %}',
+        search: 'pdf'
     }
 ];
 var supportExtraTags = [
@@ -1836,20 +1840,6 @@ function importFromUrl(url) {
     });
 }
 
-function isValidURL(str) {
-    var pattern = new RegExp('^(https?:\\/\\/)?' + // protocol
-        '((([a-z\\d]([a-z\\d-]*[a-z\\d])*)\\.)+[a-z]{2,}|' + // domain name
-        '((\\d{1,3}\\.){3}\\d{1,3}))' + // OR ip (v4) address
-        '(\\:\\d+)?(\\/[-a-z\\d%_.~+]*)*' + // port and path
-        '(\\?[;&a-z\\d%_.~+=-]*)?' + // query string
-        '(\\#[-a-z\\d_]*)?$', 'i'); // fragment locator
-    if (!pattern.test(str)) {
-        return false;
-    } else {
-        return true;
-    }
-}
-
 //mode
 ui.toolbar.mode.click(function () {
     toggleMode();