Change to triple-backtick code fences.

Former-commit-id: 81d38ed0155734a72d98b2e16425635da907aa01

vendor/docdown/README.md

@@ -12,7 +12,7 @@ For a list of upcoming features, check out our [roadmap](https://github.com/jdal
 
 Usage example:
 
-~~~ php
+```php
 require("docdown.php");
 
 // generate Markdown
@@ -20,7 +20,7 @@ $markdown = docdown(array(
   "path" => $filepath,
   "url"  => "https://github.com/username/project/blob/master/my.js"
 ));
-~~~
+```
 
 ## Author
 

vendor/docdown/src/DocDown/Entry.php

@@ -140,7 +140,7 @@ class Entry {
     preg_match('#\*\s*@example\s+([\s\S]*?)(?=\*\s\@[a-z]|\*/)#', $this->entry, $result);
     if (count($result)) {
       $result = trim(preg_replace('/(?:^|\n)\s*\* ?/', "\n", $result[1]));
-      $result = '~~~ ' . $this->lang . "\n" . $result . "\n~~~";
+      $result = '```' . $this->lang . "\n" . $result . "\n```";
     }
     return $result;
   }