dbForge Documenter for MySQL is described as 'handy MySQL and MariaDB documentation tool that automatically generates documentation of an entire MySQL database in HTML, PDF, and MARKDOWN file formats'. There are three alternatives to dbForge Documenter for MySQL for Windows, Linux and Mac. The best alternative is DbSchema. It's not free, so if you're looking for a free alternative, you could try Dataedo.
DbSchema is a visual database design & management tool. It can connect to any SQL, NoSQL or Cloud database via JDBC drivers. The tool includes features such as Relational Data Browse, Visual Query Builder, Interactive Layouts, Data Generator and more.
TechWriter for Databases is a documentation tool for databases that leverages the information locked inside your database to automatically produce database reference documentation for Access, MySQL, Oracle, SAS and SQL Server databases.