Document/allow custom panel/extensions

[rescribet]

We'd like to show additional information in the devtools (when a certain prop is available), it would be neat if the running application could provide some additional debugging views in the right pane without needing to recompile the devtools.

I'm not sure views are shareable between the render thread and the extension, but just being able to provide a plain object like the current props view would already be really helpful

E.g.

__REACT_DEVTOOLS_GLOBAL_HOOK__.addPanel('My library info', (props, ref) => {
  const customLibraryResult = someLibrary.process(props.example)

  return {
    question: 'Will be visible in the devools?',
    answer: customLibraryResult // true
  }
})

[bvaughn]

This doesn't sound like a feature we would want to support. Extensions APIs add a lot of maintenance and release complexity.

We can continue to chat about it here, but I'm going to close the issue for now because I don't think we'll take any action on it.