by Lars Wallenborn on WordPress.org
Small and efficient plugin implementing dynamic "Show more..." links. Just use the [showhide] shortcode, there is no addition to the backend.

Example view of the block editor.
This plugin allows you to easily add “Show more…” links to your site. Just enclose the content to be hidden between [showhide] and [/showhide]. There is no modification to the backend or fancy editor. Hence the code for this plugin is minimal and the plugin should be easy to review for security issues as well not impact performance.