Content Snippets
This module allows content editors to create and manage reusable pieces of text directly within Drupal. These text snippets can then be easily inserted into content or used as tokens and within Twig templates, avoiding the need to hard-code content into custom code.
Content Snippets is a simple module that provides an administrative and content editor interface for editing small bits of text that can then be used by developers when they would be otherwise tempted to hard-code content into custom code, themes, etc. Then these bits of text can be controlled by Content Editors without developer intervention. The snippets are also available as global tokens and in twig.
This module is a potentially more powerful option if you need more significant configuration options, and the ability to create new configuration pages and fields beyond just content snippets: https://www.drupal.org/project/config_pages