feat: add friend link page support using shortcode (hugo-extended version requried)

[pseudoyu]

It's common to add some friend links to our about page or seperate pages, so I add some shortcode to support this function and customized style.

The syntax is:

<div class="flink" id="article-container">
<div class="friend-list-div" >

{{< friend name="Pseudoyu" url="https://www.pseudoyu.com" logo="https://www.pseudoyu.com/images/author.webp" word="Blockchain | Programming | Photography | Boyi" >}}

</div>
</div>

[pseudoyu]

OK, I'll do some revison according to all above suggestions and resubmit. Thank you!