Bhagirath Dhanani

Allow to display comment form inside post, page and widget.
Basically comment is inbuilt feature in WordPress but in some case we need embedded comment form.
Example.
* we need to embedded comment inside post.
* some theme build without comment form for pages or custom post type.
* you want to display comment form for specific post only, so you can disable comment for all page and use shortcode to display comment.
* in custom development you need comment form inside widget.
so here we have comment form shortcode to display comment using shortcode inside post,page or widget.
Comment Form Shortcode Help
You can use below ShortCode in post or page or in widget to show comment form.
[comment comment_file =”/comments.php”]
Here comment_file is optional, if you have custom comment file, you have to pass here.
How To Use : 
[comment]
[comment comment_file =”/short-comments.php”]

Comment Form Shortcode

JorgeAmVF

autometa’s FORMA is a simple plugin that uses the following shortcode:
<ul>
<li><code>[forma]</code> = to generate a comment form.</li>
</ul>
autometa’s FORMA is a standalone component of <a href="https://wordpress.org/plugins/autometa/" rel="ugc">autometa</a> shortcodes pack.

autometa's FORMA

It generates comment forms in posts simply via: [forma].

Comment Form Shortcode vs autometa's FORMA