TinyMCE editor
I have used this editor within web applications that has a rich set of features.
It has both Cloud and self-hosting options.
This angular front end framework integration guide is a good place to start to try this editor:
This project has a very good set of documentation.
This 'basic example' https://www.tiny.cloud/docs/tinymce/6/basic-example/ and other guides would get you started right away to use this editor in your web application/web site.