## 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
operations[i++] = TREE_OPERATION_REMOVE;
      
      operations[i++] = numUnmountIDs;
      
      for (let j = 0; j < pendingUnmountedIDs.length; j++) {
        operations[i++] = pendingUnmountedIDs[j];
      }
      
      if (pendingUnmountedRootID !== null) {
        operations[i] = pendingUnmountedRootID;
        i++;
      }
    }
    
    for (let j = 0; j < pendingOperations.length; j++) {
      operations[i + j] = pendingOperations[j];
    }
    i += pendingOperations.length;
    if (__DEBUG__) {
      printOperationsArray(operations);
    }
    
    hook.emit('operations', operations);
    pendingOperations.length = 0;
    pendingUnmountedIDs = [];
    pendingUnmountedRootID = null;
    pendingStringTable.clear();
    pendingStringTableLength = 0;
  }
  function pushOperation(op: number): void {