HTML 5 elements missing from hardcoded element lists

```
_HashHTMLBlocks has a hardcoded list of block elements. This is missing new
block elements from HTML 5. The current set of defined block elements is:

address,applet,blockquote,button,center,dd,del,dir,div,dl,dt,fieldset,form,frame
set,hr,iframe,ins,isindex,li,map,menu,noframes,noscript,object,ol,p,pre,script,t
able,tbody,td,tfoot,th,thead,tr,ul,article,aside,details,dialog,summary,figure,f
ooter,header,hgroup,nav,section,audio,video,canvas,datalist

```

Original issue reported on code.google.com by `wich...@outlook.com` on 22 Feb 2013 at 9:25

在程式碼庫中尋找 _HashHTMLBlocks 函式，它可能位於核心 Markdown 處理檔案中。該 issue 列出了缺少的 HTML5 區塊元素；將函式中的硬編碼清單與提供的清單進行比較。將缺少的元素 (article, aside, details, dialog, summary, figure, footer, header, hgroup, nav, section, audio, video, canvas, datalist) 新增至陣列中。透過處理包含這些元素的 Markdown 進行測試，確保它們會被視為區塊元素。

由索引模型根據 Issue 內容生成。