nnm-club besides the default that comes shipped with Flarum there is also a rich text editor extension available. If you want something different to be integrated to Flarum this will have to done as an extension. If you want to propose that, you can do so in the proposal tag. If it receives enough upvotes someone might pick it up. Besides that you could describe a request in the services tag for a professional that you pay to pick this up. If you want to develop this yourself you might want to ask your questions in the dev tag. You can start by reading the documentation.
