What services are good for building, editing, and reviewing content?

We use https://www.typeform.com/ on our e-learning platform to create engaging content.

However, we are now looking at building a new creator suite feature. This will give users the ability to create/ edit their own content.

Does anyone know of any services that are good for building, editing, reviewing etc. content?

It would be great if we could embed this tool into our site but not a deal breaker.

Example of tools that we are looking at:

• https://www.easygenerator.com/