interfacelab

NOTE: This plugin requires PHP 7.1x or higher
The ILAB Docs plugin allows you to integrate help documentation for your WordPress theme or plugin directly 
into the WordPress admin.
Documentation is written in Markdown, with special extensions that make writing documentation in markdown easy. These 
extensions allow linking to other markdown files, linking to admin pages, video embeds, displaying a table of contents 
and other features. ILab Docs also has integrated search functionality for easily searching your documentation.
For examples integrating this documentation plugin with your plugin or theme, check out these examples:
<ul>
<li><a href="https://github.com/Interfacelab/ilab-docs-example-plugin" rel="nofollow ugc">Example plugin with documentation</a></li>
<li><a href="https://github.com/Interfacelab/ilab-docs-example-theme" rel="nofollow ugc">Example theme with documentation</a></li>
</ul>

WP Help Docs

Directly integrate markdown based help documentation for your WordPress theme or plugin into the WordPress admin for your end users and clients.

dinamiko

Docu is a simple but flexible documentation plugin that allows you to document your products with ease.
<h4>Features</h4>
<ul>
<li>Order Doc Categories and Docs with drag and drop in the admin</li>
<li>Docu Sidebar Widget that displays a search form and a list of all categories</li>
<li>Flexible template system that allows template overrides in an upgrade safe way</li>
<li>Well documented, it’s a documentation plugin 🙂</li>
</ul>
<h3>Credits</h3>
The creation of class-docu-template-loader.php was taken from a tutorial of pippinsplugins.com
This plugin uses Masonry and imagesloaded 
http://masonry.desandro.com 
https://github.com/desandro/imagesloaded

WP Help Docs vs Docu