## The current behavior

The full value of the `key` is very difficult / impossible to find and use in the interface of the React Devtools.

![Kapture 2020-04-22 at 11 47 47](https://user-images.githubusercontent.com/1935696/79997715-25222680-84ba-11ea-97ba-51f1679a8c91.gif)

Only managed to find it by accident :(

## The expected behavior

The `key` is visible in the props list to the right.

### Detailed Proposal

As mentioned below in https://github.com/facebook/react/issues/18702#issuecomment-617924196

Add a light divider and new section in the props panel to the right.

Potentially also add a question mark that shows an explanation about the fact that things in this section are not really props.

Ref (Original implementation): https://github.com/facebook/react-devtools/pull/328
id: getFiberID(getPrimaryFiber(fiber)),
      isFullMatch: trackedPathMatchDepth === trackedPath.length - 1,
    };
  }
  const formatPriorityLevel = (priorityLevel: ?number) => {
    if (priorityLevel == null) {
      return 'Unknown';
    }
    switch (priorityLevel) {
      case ImmediatePriority:
        return 'Immediate';
      case UserBlockingPriority:
        return 'User-Blocking';
      case NormalPriority:
        return 'Normal';
      case LowPriority:
        return 'Low';
      case IdlePriority:
        return 'Idle';
      case NoPriority:
      default:
        return 'Unknown';
    }
  };
  function setTraceUpdatesEnabled(isEnabled: boolean): void {
    traceUpdatesEnabled = isEnabled;
  }
  return {
    cleanup,
    copyElementPath,