## 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
const ownerID =
        internalInstance._currentElement != null &&
        internalInstance._currentElement._owner != null
          ? getID(internalInstance._currentElement._owner)
          : 0;
      const displayNameStringID = getStringID(displayName);
      const keyStringID = getStringID(key);
      pushOperation(TREE_OPERATION_ADD);
      pushOperation(id);
      pushOperation(type);
      pushOperation(parentID);
      pushOperation(ownerID);
      pushOperation(displayNameStringID);
      pushOperation(keyStringID);
    }
  }
  function recordReorder(
    internalInstance: InternalInstance,
    id: number,
    nextChildren: Array<InternalInstance>,
  ) {
    pushOperation(TREE_OPERATION_REORDER_CHILDREN);
    pushOperation(id);
    const nextChildIDs = nextChildren.map(getID);
    pushOperation(nextChildIDs.length);
    for (let i = 0; i < nextChildIDs.length; i++) {
      pushOperation(nextChildIDs[i]);
    }
  }
  function recordUnmount(internalInstance: InternalInstance, id: number) {