Adding table of contents to docs

Cras at dolor eget urna varius faucibus tempus in elit. Cras a dui imperdiet, tempus metus quis, pharetra turpis.

Add the following code at the top of the post:

#### Sections in this article
{:.no_toc}
* TOC
{:toc}

{:.no_toc} exludes #### Sections in this article title from indexing in table of contents


Adding media to post and doc content
Thêm cảnh báo vào nội dung